1. n 2008 a n n u a l r ep or t

2. On the Job 2 Financial Highlights 14 On Your Side 4 Officers and Directors 16 On Strategy 6Form 10-K Letter to Shareholders 9 Investor Information Inside back cover 3. n on the job on your sideon strategy 4. on the job throughout 2008, we remained focused on our customers. We madesignificant investments in our energy infrastructure and forgedstrong partnerships with our customers and communities, improvingoverall reliability and customer satisfaction. through amerenuespower on reliability program in Missouri, in 2008 we completed250 undergrounding projects, burying more than 100 miles of electricline. We trimmed trees along more than 6,500 miles of overheadline, tested nearly 100,000 wood utility poles and inspected morethan 8,000 miles of electric line all to improve customer reliability.this initiative resulted in a much lower number of outages during2008 weather events. In Illinois, targeting the worst-performing circuits and aggressivelytrimming trees also yielded significant reliability improvements. Illinoiscrews performance on gas leak calls with an average responsetime of less than 23 minutes placed amerens Illinois utilities amongthe leaders in industry rankings. In both states, ratings in surveys conducted with customers whohad contact with amerens utility companies were among thehighest ever experienced, and ratings of general satisfactionalso improved. across Illinois and Missouri in 2008, our utilitycompanies can be credited with distinguished performance, reducingthe frequency of service interruptions and per-customer outages byn15 percent since 2004 to earn a top-quartile industry ranking. 23 5. ensuring safe, reliable service 6. on your side environmental stewardship is a cornerstone of performanceleadership at ameren. over the years, our power plants have beenindustry leaders in reducing emissions by piloting new technologiesand investing in research. In 2008, we began installing scrubbers sophisticated emissions-reduction equipment at three plants. these nnew, state-of-the-art controls are expected to eliminate almost allsulfur dioxide emissions at these facilities. at amerenue, a comprehensive integrated resource planningprocess calls for the combination of energy efficiency initiatives andrenewable resources as the best way to delay the need for buildinglarge generating plants. In executing this plan, we are launchingaggressive initiatives to help customers use energy more efficiently.a range of customer programs are aimed at helping customerschange their approach to using energy, with a goal of saving540 megawatts of generation by 2025 the equivalent of a mid-sizedcoal-fired plant. amerenue has also committed to add wind powerto its generation portfolio and continues to sponsor and promote avoluntary renewable energy program for electric customers. Illinois law has set aggressive annual energy efficiency savingsgoals. In 2008, we began offering incentives on electric energy-efficient systems to our Illinois customers, and amerens Illinois(Photo at right) Jeremy Dyer, Director ofOperations C-Store Division, Niemannutilities have also created actonenergy.com, a dynamic new WebFoods, right, discusses energy efficiencywith Rusty Tribe, an Ameren Illinoissite to provide energy-saving advice and program information.utilities ActOnEnergy representative.amerens purchase of renewable energy credits in Illinois alsoWith a three-year electric and natural gasbudget of $100 million, ActOnEnergy isdemonstrates the companys commitment.an incentive program for Ameren Illinoisutilities electric and natural gas distribu-tion customers. Niemann Foods receivedmore than $212,000 for projects thatwill make 27 Illinois grocery storesmore energy efficient. 45 7. providing energy savings options and protecting the environment 8. on strategy even though the current economic environment has createdchallenges for our industry and our company, we have plans inplace to stay on strategy. that strategy calls for investing in ourIllinois and Missouri regulated businesses to deliver safe, reliableand affordable energy in an environmentally responsible manner.our strategy also calls for optimizing our existing non-rate-regulatedgeneration assets. together, these initiatives should deliver solid,MeanIngFullong-term value to our shareholders.InvestMent In servIngCustoMersalso key to our strategic plan is our concept of the cycle shownon this page: that cycle begins with prudent investments in HIgH infrastructure. Making these investments helps us improve service, FaIrQualItyreturn onwhich, in turn, leads to higher customer satisfaction. ImprovedservICe InvestMent service and satisfaction should translate into fair treatment by ourregulators. Better regulatory treatment should result in improvedreturns on investment for our regulated electric and naturalHIgH CustoMergas operations bringing returns to levels that are necessary tosatIsFaCtIoncost-effectively fund further infrastructure investment. all thisshould lead to a continuation of this cycle and long-term benefitsnto our shareholders.67 9. building long-termfundamental value 10. n 11. my fellow shareholdersthe theme of our 2008 report is simple: We are on the job, on your side and focused on our strategy.the evidence of our progress on these initiatives is plentiful, from improved reliability statistics to higher customer satisfaction ratings, from strong power plant performance to much-needed rate increases for our regulated operations both in Illinois and Missouri.I will address these later, but one of our most critical 2008 accomplishments is that we acted strategically to respond to the dramatic economic downturn, volatile commodity markets and unprecedented strains in capital and credit markets.We took timely, prudent actions to increase our liquidity and enhance our financial flexibility, accessing the capital markets and significantly reducing our 2008 and projected 2009 spending. We put in place plans to slash projected capital and operating expenditures by approximately $800 million. We reduced executive management salaries and incentive compensation opportunities and established firm controls on headcount. We have always tightly managed our operations, maintenance and administrative expenses, but we are taking it to a new level.Amerens Executive Leadership Team: (From left) Adam C. Heflin, Senior Vice President and Chief Nuclear Officer, AmerenUE; Donna K. Martin, Senior Vice President and Chief Human Resources Officer; Daniel F. Cole, Senior Vice President, Administration and Technical Services, Ameren Services; Scott A. Cisel, President and Chief Executive Officer, AmerenCilCO, AmerenCiPS and AmereniP; Gary L. Rainwater, Chairman, President and Chief Executive Officer; Andrew M. Serri, President, Ameren Energy Marketing; Thomas R. Voss, Executive Vice President and Chief Operating Officer, President and Chief Executive Officer, AmerenUE; Charles D. Naslund, President and Chief Executive Officer, Ameren Energy Resources; Warner L. Baxter, Executive Vice President and Chief Financial Officer, President and Chief Executive Officer, Ameren Services; Richard J. Mark, Senior Vice President, Energy Delivery, AmerenUE; Martin J. Lyons, Jr., Senior Vice President and Chief Accounting Officer; Steven R. Sullivan, Senior Vice President, General Counsel and Secretary; and Michael L. Moehn, Senior Vice President, Corporate Planning and Risk Management, Ameren Services. 89 12. as part of these efforts, amerens Board of Directors companies, as compared to the 88 percent paid out reduced the common share dividend level byby ameren in 2008. 39 percent in early 2009. your board did not make By setting a new, more realistic level, we can retain this decision lightly. amerens directors realized approximately $215 million a year. this additional that the corporation was faced with the prospect of cash will help us enhance reliability, meet our abandoning a strategic plan that we firmly believe customers expectations and grow our regulated will deliver long-term value to you, our investors. businesses. It will also reduce our reliance on Had we not reduced the dividend, we would have dilutive equity financings, enhance our access to been forced to turn to high-cost financings to the capital and credit markets and drive solid, long- support the execution of that plan.n term earnings-per-share growth. AmerenUE is installing weather stations on existing AmerenUE poles in key locations throughout the region to measure temperature and wind speed, among other variables. AmerenUE joined Saint Louis Universitys Department of Earth & Atmospheric Sciences to create Quantum Weather, a highly precise weather monitoring, forecasting and response system that improves efficiency and speeds up power restoration. We are FoCuseD on DelIverIng some background on the dividend: the previous level was established at a time when amerens saFe, relIaBle anD aFForDaBle earnings were fully regulated and more predict- energy, WHIle aCHIevIng solID able. In 2008, almost 60 percent of amerens returns. groWIng our InvestMent earnings came from its non-rate-regulated genera- In our regulateD BusInesses WIll tion business. these earnings are subject to wide InCrease CustoMer satIsFaCtIon fluctuations based on market-driven power prices. tHrougH exCellent servICe. Continued dependence on this volatile earnings stream cannot support a large dividend, and our dividend was sizeable. In recent years, amerens In the end, this action will make ameren stronger annual dividend payout has totaled over half a and more nimble able to access the capital billion dollars a payout ratio that was among the markets on more favorable terms. highest in the industry and the nation.More importantly, we can use these incremental our adjusted dividend level provides us with a more funds to continue to pursue the following straightfor- sustainable payout ratio, based upon earnings ward, long-term business strategies to deliver solid, primarily from our regulated businesses. It also long-term value to you, our shareholders: puts our new dividend payout ratio squarely in line with ratios of 50 to 60 percent of earnings for peer 13. A Commitment To Investing In Our Illinois In 2008, we also worked to balance the need to and Missouri Regulated Businesses. We are invest in regulated delivery and generation infra- focused on delivering safe, reliable and affordable structure with the need to provide reasonable rates. energy, while achieving solid returns. growingIn addition, we aggressively sought recovery of our investment in our regulated businessesthese prudent investments to improve our returns. will increase customer satisfaction through Building Constructive Regulatory Frame- excellent service. works. Being on means recognizing the impact In 2008, we succeeded in doing just that. on theregulatory decisions have on earnings and credit delivery side of our business, reliability improved,ratings that affect our ability to cost effectively raise and customer satisfaction survey ratings rose.capital and invest in our businesses. In both Illinois For generating stations across Amerens service territory, the Performance Monitoring Center continuously monitors plant equipment performance through pattern recognition software tools and real-time support. The center provides early stage notification of any equipment degradation or pending equipment failure to avoid extended outages that could hurt power plant availability. amerenues power on reliability program and Missouri, we have worked hard to achieve contributed to a much lower number of outages constructive regulatory outcomes, given our need during storms. Both the Illinois and Missouri to update rates to levels that reflect todays much delivery companies earned top-quartile industry higher costs. our three Illinois electric and natural rankings by reducing service interruption frequency gas delivery companies were authorized to raise a key reliability measure.rates by $161 million, effective october 1, 2008. amerenue received a $162 million electric rate our focus on achieving operational excellence atincrease in Missouri, which took effect March 1, 2009. our regulated generating plants has also yieldedHowever, even with this recent increase, amerenue strong results with our Callaway nuclear plantrates remain well below the national average. leading the way. In 2008, Callaway completed a record run of 520 consecutive days and itsthe most recent Missouri rate case also granted shortest refueling and maintenance outage ever. approval for recovering fuel and purchased power our coal-fired plants also performed well, with costs on a timely basis. By offering greater stability another year of solid availability. one notable mile- of earnings and cash flows, this provision bolsters stone: labadie power plant in Missouri generatedour ability to continue to raise capital and invest in more than a half-billion-megawatthours one of our utility infrastructure. only a few coal-fired plants in the nation to achieve that level.10 11 14. In 2008, Core earnIngs atour non-rate-regulateD Optimizing Our Existing non-Rate-RegulatedgeneratIon operatIons rose Generation Assets. In 2008, core earnings atalMost 11 perCent BeCause tHe our non-rate-regulated generation operations roseplants stayeD On IMprovIng almost 11 percent because the plants stayedoutput anD MargIns. on improving output and margins.unfortunately, power and fuel markets have recentlyFor all these reasons, we are focused on this issue. exhibited extreme price volatility. However, our We have been actively working to frame reasonable prudent hedging policies are expected to preservelegislation and regulation, while we have acted to value in 2009 and beyond. as we manage our address climate change. our efforts range from investment in non-rate-regulated generationparticipating in research projects on clean coal andA new scrubber (left) is being installed at our Duck Creek PowerPlant in Canton, near Peoria, Ill. (above). Slated for completion in2009, the scrubber operates like a chemical plant and, along withan existing selective catalytic reduction system, will dramaticallyreduce sulfur dioxide and mercury emissions, positioning this non-rate-regulated generating plant to comply with state and federalclean air regulations.operations, we will continue to closely monitorcarbon capture storage technologies to increasing market movements and the regulatory landscape. operating efficiencies at our nuclear and hydro- In 2008, we began to install state-of-the-art environ- electric plants. mental controls at some of our non-rate-regulatedameren is also on when it comes to encouraging coal-fired plants to extend their lives in the face ofenergy efficiency. In early 2008, amerenue filed increasingly stringent federal and state emissionsan integrated resource plan with the Missouri public reduction regulations.service Commission detailing how the company Demonstrating Environmental Leadership.expects to supply electricity in coming years. after We continue to maintain an active presence ina year-long process involving dozens of meetings discussions related to the need to address climate with stakeholders and intensive analysis, the change by reducing greenhouse gas emissionscompany filed a preferred plan that calls for from our coal-fired plants. our current analysis increasing efficiency initiatives and renewable of various policy scenarios now being debated in energy development. Both in Illinois and Missouri, Washington shows that, if implemented, they couldwe are launching a number of programs aimed at cause household costs and rates for electricityhelping customers reduce energy use. the ameren to rise significantly. the Midwest economy isIllinois utilities have raised customer energy aware- especially vulnerable to economic dislocation givenness with an award-winning actonenergy Web site its reliance on coal-fired power.(www.actonenergy.com). 15. In Missouri, amerenue plans to add at least growth target of at least 5 percent. Coupled with 100 megawatts of wind power by 2010 and antici- the new common dividend rate, this would provide pates up to an additional 225 megawatts by 2020.competitive, long-term total return potential. even- the company is working to supply electric genera- tually, our goal would be to grow the dividend level tion from wind and landfill gas, while participating in as our earnings from rate-regulated operations studies on potential biomass fuel sources, lookingincrease and our overall cash profile improves. into hydroelectric generation facilities on local rivers We are confident that execution of this plan will and investigating development of solar generation. deliver solid, long-term returns for our shareholders amerenue has also launched a voluntary renew- as the economy and energy markets recover. We able energy credit customer program, which inn understand that you our owners depend on us 2008, was named the new green power programShown here are the cooling tower and a simulated control room used fortraining at AmerenUEs Callaway Nuclear Plant, where in October 2008,employees completed a record run of 520 consecutive days, which beganin May 2007. Callaway is one of only 26 of the nations 104 nuclear plantsto achieve a record run of more than 500 days. of the year by the u.s. Department of energy, the to turn challenges into opportunities for sustained u.s. environmental protection agency and thegrowth. We have the strategies, the people and the Center for resource solutions. In Illinois, we areassets to do just that. We are on it. purchasing renewable energy credits. We want to thank you for your continued support However, we know this will not be enough. during this difficult period, and we thank our amerenue expects to need new generation byemployees for their dedication and for incorporating the 2018 to 2020 timeframe. thats why in 2008our values in everything they do. amerenue moved to preserve the option for a I hope you can attend this years annual share- possible second nuclear unit at its existing Callaway holders Meeting on april 28 at the Chase park plant site. no decision on building a unit has been plaza Hotel in st. louis. made. But by applying for a license to possibly build a unit, we began the regulatory process and made the unit eligible for billions of dollars in federal incen- tives established by the energy policy act of 2005. gary l. raInWater CHaIrMan, presIDent anD ameren is on the path to earnings growth. We CHIeF exeCutIve oFFICer expect execution of our strategy to enable us toaMeren CorporatIon March 2, 2009 achieve a long-term, annual earnings-per-share 12 13 16. Financial Highlights Year Ended December 31, aMeren ConsolIDateD (In millions, except per share amounts and as noted) 20072006 2008 results oF operatIons $7,839 operating revenues $7,562$6,895 $6,477 operating expenses $6,203$5,707 $1,362 operating income $1,359$1,188 $605 net income $618$547CoMMon stoCk Data$2.88 earnings per basic and diluted share$2.98 $2.66$2.54 Dividends per common share$2.54 $2.547.6% Dividend yield (year-end) 4.7%4.7% $33.26 Market price per common share (year-end closing) $54.21$53.73210.1 shares outstanding (weighted average) 207.4 205.6 $7,062 total market value of common shares (year-end)$11,294 $11,099 $32.80 Book value per common share$32.41$31.87BalanCe sHeet Data$16,567 property and plant, net $15,069 $14,286$22,657 total assets$20,728 $19,635 $6,554 long-term debt obligations, excluding current maturities $5,689$5,285 Capitalization ratios 45.9%Common equity48.2%50.6%1.3%preferred stock, not subject to mandatory redemption1.4% 1.5% 52.8%Debt and preferred stock subject to mandatory redemption, net of cash50.4%47.9%operatIng Data107,754 total electric sales (kilowatthours)107,486 101,015119,712 native natural gas sales (decatherms in thousands)107,871 108,682 80,859 total generation output (kilowatthours)81,36781,485 2.4 electric customers 2.4 2.4 1.0 natural gas customers1.0 1.0 17. 6,500 megawatts generating capacity in Illinois3,400,000ameren employees, numbering approximately9,500, serve approximately 2.4 million electricelectric and naturalgas customers and nearly one million natural gas customers overPeoria64,000 square miles in Illinois and Missouri. thecompanys service territory includes a diverseSpringfield base of residential, commercial and large industrialcustomers in both urban and rural areas. In DecaturMissouri, we operate primarily as a traditional,rate-regulated utility with about 10,000 megawattsSt. Louisof generating capacity. our Illinois operations10,000 include rate-regulated electric and natural gastransmission and distribution businesses, as well megawatts generating capacity in Missourias a non-rate-regulated generating businesswith a capacity of approximately 6,500 megawattsof generation. today, amerens Missouri company,Company andSubsidiary Headquartersamerenue, is the largest electric utility in the state,Electric Service Territorywhile the Illinois operations make ameren theElectric and Natural Gassecond largest electric distribution company andService Territoryone of the largest distributors of natural gas inthat state. total natIve total CapItal eleCtrICnaturalgeneratIonInvestMents sales gas salesoutput 119,712 $1,896 108,682 107,871107,486107,754 101,01581,485 81,367 80,859$1, 381(Decatherms in thousands)$1,284(kilowatthours in millions)(kilowatthours in millions) (In millions) 06 07 0806 0708 06 07 08060708 14 15 18. Ameren Corporation and Subsidiaries Officers and Directors exeCutIve leaDersHIp teaM Michael L. Moehn*Scott A. Cisel* Daniel F. Cole* Gary L. Rainwater Senior Vice President, Chairman, PresidentPresident and Chief Senior Vice President, Corporate Planning and Risk and Chief Executive OfficerExecutive Officer,Administration and Technical Management,AmerenCILCO, AmerenCIPS,Services, Ameren Services Warner L. Baxter Ameren ServicesAmerenIPAdam C. Heflin* Executive Vice President Charles D. Naslund* and Chief Financial Officer; Senior Vice President andDonna K. Martin President and Chief Executive President and Chief ExecutiveSenior Vice President Chief Nuclear Officer, Officer, Ameren Energy Resources; Officer, Ameren Services and Chief Human AmerenUE President, Ameren EnergyResources Officer Thomas R. Voss Martin J. Lyons, Jr. Generating Company Executive Vice President Senior Vice PresidentSteven R. Sullivan Andrew M. Serri* and Chief Operating Officer; Senior Vice President,and Chief Accounting Officer President, President and Chief ExecutiveGeneral Counsel and Richard J. Mark* Ameren Energy Marketing Officer, AmerenUESecretary Senior Vice President,Energy Delivery, AmerenUEJohn R. Fey* Michael L. Menne*Joseph M. Power* otHer oFFICers Vice President, HumanVice President,Vice President, FederalBarnes* Lynn M. Resources, Business Services,Environmental Safety and Health, Legislative and Regulatory Vice President, Business Planning Ameren ServicesAmeren ServicesAffairs, Ameren Services and Controller, AmerenUEDonald M. Mosier*William J. Prebil* Karen C. Foss* Jerre E. Birdsong Vice President, Public Relations,Vice President,Vice President, Vice President and Treasurer AmerenUE Ameren Energy MarketingRegional Operations, Mark C. Birk* AmerenCILCO, AmerenCIPS, Michael J. Getz* Michael G. Mueller* Vice President, AmerenIP Controller,President, Ameren Energy Power Operations, AmerenUE David J. Schepers* AmerenCILCO, AmerenCIPS, Fuels and Services Maureen A. Borkowski* AmerenIPVice President, EnergyRobert K. Neff* Vice President, Transmission, Delivery Technical Services, Scott A. Glaeser*Vice President, Coal Supply Ameren Services Ameren Services Vice President, Gas Supply and Transportation, S. Mark Brawley*Shawn E. Schukar* and System Control,Ameren Energy Fuels and Vice President, Internal Audit, Ameren Energy FuelsServices Vice President, Strategic Ameren Services and ServicesInitiatives, Ameren ServicesCraig D. Nelson* Charles A. Bremer* Timothy E. Herrmann*Vice President, Regulatory Affairs Jerry L. Simpson* Vice President, InformationVice President, Engineering,and Financial Services, Ameren- Vice President, Business Technology and AmerenCallaway Nuclear Plant, CILCO, AmerenCIPS, AmerenIP Services, Ameren Energy Services Center, Ameren Services AmerenUE ResourcesGregory L. Nelson* Richard C. Cissell*Christopher A. Iselin* James A. Sobule*Vice President and Tax Counsel, Vice President, Operations,Vice President, GenerationAmeren ServicesVice President and Ameren Energy Generating Technical Services,Deputy General Counsel,Stan E. Ogden*Ameren Energy ResourcesAmeren Services Kevin DeGraw*Vice President, Customer Vice President,Stephen M. Kidwell* Service and Public Relations,Bruce A. Steinke Corporate Project Risk Vice President, AmerenCILCO, AmerenCIPS, Vice President and Controller Management, Ameren ServicesRegulatory Affairs, AmerenUEAmerenIP Dennis W. Weisenborn* Fadi Diya* Mark C. Lindgren* Ronald D. Pate*Vice President, Vice President,Vice President, Corporate Vice President, Regional Supply Services, Ameren Nuclear Operations, AmerenUE Human Resources,Operations, AmerenCILCO, ServicesAmeren Services AmerenCIPS, AmerenIP Ronald K. Evans*Ronald C. Zdellar* Vice President andVice President, Energy Deputy General Counsel, Delivery Distribution Services, Ameren Services AmerenUE BoarD oF DIreCtors Dr. Gayle P. W. Jackson 5, 6Gary L. Rainwater1 Member of Finance CommitteePresident, Energy Global, Inc.Chairman, President2 Member of Audit and Risk Committee Stephen F. Brauer 1, 2and Chief Executive Officer, 3 Member of Human ResourcesJames C. Johnson 3, 4 Chairman and ChiefAmeren Corporation CommitteeVice President and Executive Officer, Hunter 4 Member of Nominating and CorporateAssistant General Counsel,Harvey Saligman 3, 4 Engineering Company Governance CommitteeCommercial Airplanes, Partner, Cynwyd Investments Susan S. Elliott 2, 6 5 Member of Public Policy CommitteeThe Boeing CompanyPatrick T. Stokes 3, 4, 7 Chairman and Chief Executive6 Member of Nuclear OversightFormer Chairman,Charles W. Mueller 1, 5, 6 Officer, Systems ServiceCommitteeRetired Chairman andAnheuser-Busch Enterprises, Inc. 7 Lead DirectorChief Executive Officer,Companies, Inc. Walter J. Galvin 1, 3Ameren CorporationJack D. Woodard 5, 6 Senior Executive ViceRetired Executive ViceDouglas R. Oberhelman 2, 4 President and ChiefGroup President, Caterpillar Inc. President and Chief Nuclear Financial Officer,Officer, Southern Nuclear Emerson Electric Co.Operating Company, Inc. As of March 2, 2009 16 * Officer of an Ameren Corporation subsidiary only 19. UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549FORM 10-K (X) Annual report pursuant to Section 13 or 15(d)of the Securities Exchange Act of 1934for the fiscal year ended December 31, 2008 OR( ) Transition report pursuant to Section 13 or 15(d)of the Securities Exchange Act of 1934for the transition period fromto. Exact name of registrant as specified in its charter; CommissionState of Incorporation;IRS Employer File Number Address and Telephone Number Identification No. 1-14756 Ameren Corporation 43-1723446 (Missouri Corporation) 1901 Chouteau Avenue St. Louis, Missouri 63103 (314) 621-32221-2967Union Electric Company 43-0559760 (Missouri Corporation) 1901 Chouteau Avenue St. Louis, Missouri 63103 (314) 621-32221-3672Central Illinois Public Service Company37-0211380 (Illinois Corporation) 607 East Adams Street Springfield, Illinois 62739 (888) 789-2477333-56594 Ameren Energy Generating Company 37-1395586 (Illinois Corporation) 1901 Chouteau Avenue St. Louis, Missouri 63103 (314) 621-32222-95569 CILCORP Inc. 37-1169387 (Illinois Corporation) 300 Liberty Street Peoria, Illinois 61602 (309) 677-52711-2732Central Illinois Light Company 37-0211050 (Illinois Corporation) 300 Liberty Street Peoria, Illinois 61602 (309) 677-52711-3004Illinois Power Company 37-0344645 (Illinois Corporation) 370 South Main Street Decatur, Illinois 62523 (217) 424-6600 20. Securities Registered Pursuant to Section 12(b) of the Securities Exchange Act of 1934:The following securities are registered pursuant to Section 12(b) of the Securities Exchange Act of 1934 and are listed on the New York Stock Exchange: RegistrantTitle of each class Ameren CorporationCommon Stock, $0.01 par value per share Securities Registered Pursuant to Section 12(g) of the Securities Exchange Act of 1934: RegistrantTitle of each class Union Electric CompanyPreferred Stock, cumulative, no par value, stated value $100 per share $4.56 Series $4.50 Series $4.00 Series $3.50 Series Central Illinois Public Service Company Preferred Stock, cumulative, $100 par value per share 6.625% Series4.90% Series 5.16% Series 4.25% Series 4.92% Series 4.00% Series Depository Shares, each representing one-fourth of a share of 6.625% Preferred Stock, cumulative, $100 par value per share Central Illinois Light CompanyPreferred Stock, cumulative, $100 par value per share 4.50% SeriesAmeren Energy Generating Company, CILCORP Inc., and Illinois Power Company do not have securities registered under either Section 12(b) or 12(g) of the Securities Exchange Act of 1934. Indicate by check mark if each registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act of 1933.Ameren CorporationYes (X)No()Union Electric CompanyYes (X)No()Central Illinois Public Service Company Yes () No(X)Ameren Energy Generating CompanyYes () No(X)CILCORP Inc.Yes () No(X)Central Illinois Light CompanyYes () No(X)Illinois Power CompanyYes () No(X) Indicate by check mark if each registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934.Ameren Corporation No(X)Yes( )Union Electric Company No(X)Yes( )Central Illinois Public Service CompanyNo(X)Yes( )Ameren Energy Generating Company No(X)Yes( )CILCORP Inc. (X) NoYes()Central Illinois Light Company No(X)Yes()Illinois Power Company No(X)Yes() Indicate by check mark whether the registrants: (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) have been subject to such filing requirements for the past 90 days.Ameren CorporationYes (X)No( )Union Electric CompanyYes (X)No( )Central Illinois Public Service Company Yes (X)No( )Ameren Energy Generating CompanyYes (X)No( )Central Illinois Light CompanyYes (X)No( )Illinois Power CompanyYes (X)No( )CILCORP has voluntarily filed all reports that it would have been required to file if it had been subject to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months. 21. Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of each registrants knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.Ameren Corporation()Union Electric Company(X)Central Illinois Public Service Company (X)Ameren Energy Generating Company(X)CILCORP Inc.(X)Central Illinois Light Company(X)Illinois Power Company(X)Indicate by check mark whether each registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See definitions of large accelerated filer, accelerated filer, and smaller reporting company in Rule 12b-2 of the Securities Exchange Act of 1934.LargeSmallerAccelerated Accelerated Non-accelerated Reporting Filer Filer FilerCompanyAmeren Corporation (X) ()()()Union Electric Company ()()(X) ()Central Illinois Public Service Company()()(X) ()Ameren Energy Generating Company ()()(X) ()CILCORP Inc. ()()(X) ()Central Illinois Light Company ()()(X) ()Illinois Power Company ()()(X) ()Indicate by check mark whether each registrant is a shell company (as defined in Rule 12b-2 of the Securities Exchange Act of 1934).Ameren CorporationYes()No (X)Union Electric CompanyYes()No (X)Central Illinois Public Service Company Yes()No (X)Ameren Energy Generating CompanyYes()No (X)CILCORP Inc.Yes()No (X)Central Illinois Light CompanyYes()No (X)Illinois Power CompanyYes()No (X) As of June 30, 2008, Ameren Corporation had 210,050,075 shares of its $0.01 par value common stock outstanding. The aggregate market value of these shares of common stock (based upon the closing price of these shares on the New York Stock Exchange on that date) held by nonaffiliates was $8,870,414,667. The shares of common stock of the other registrants were held by affiliates as of June 30, 2008.The number of shares outstanding of each registrants classes of common stock as of January 30, 2009, was as follows: Ameren CorporationCommon stock, $0.01 par value per share: 212,519,772 Union Electric CompanyCommon stock, $5 par value per share, held by Ameren Corporation (parent company of the registrant): 102,123,834 Central Illinois Public Service Company Common stock, no par value, held by Ameren Corporation (parent company of the registrant): 25,452,373 Ameren Energy Generating CompanyCommon stock, no par value, held by Ameren Energy Resources Company, LLC (parent company of the registrant and subsidiary of Ameren Corporation): 2,000 CILCORP Inc.Common stock, no par value, held by Ameren Corporation (parent company of the registrant): 1,000 Central Illinois Light CompanyCommon stock, no par value, held by CILCORP Inc. (parent company of the registrant and subsidiary of Ameren Corporation): 13,563,871 Illinois Power CompanyCommon stock, no par value, held by Ameren Corporation (parent company of the registrant): 23,000,000 22. DOCUMENTS INCORPORATED BY REFERENCE Portions of the definitive proxy statement of Ameren Corporation and portions of the definitive information statements of Union Electric Company, Central Illinois Public Service Company, and Central Illinois Light Company for the 2009 annual meetings of shareholders are incorporated by reference into Part III of this Form 10-K.OMISSION OF CERTAIN INFORMATIONAmeren Energy Generating Company and CILCORP Inc. meet the conditions set forth in General Instruction I(1)(a) and (b) of Form 10-K and are therefore filing this form with the reduced disclosure format allowed under that General Instruction.This combined Form 10-K is separately filed by Ameren Corporation, Union Electric Company, Central Illinois Public Service Company, Ameren Energy Generating Company, CILCORP Inc., Central Illinois Light Company, and Illinois Power Company. Each registrant hereto is filing on its own behalf all of the information contained in this annual report that relates to such registrant. Each registrant hereto is not filing any information that does not relate to such registrant, and therefore makes no representation as to any such information. 23. TABLE OF CONTENTS PageGLOSSARY OF TERMS AND ABBREVIATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 Forward-looking Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 PART I Item 1.Business . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Business Segments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Rates and Regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Supply for Electric Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Natural Gas Supply for Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Industry Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Operating Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Available Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Item 1A. Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Item 1B. Unresolved Staff Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 Item 2.Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Item 3.Legal Proceedings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 Item 4.Submission of Matters to a Vote of Security Holders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 Executive Officers of the Registrants (Item 401(b) of Regulation S-K) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 PART II Item 5.Market for Registrants Common Equity, Related Stockholder Matters, and Issuer Purchases of EquitySecurities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Item 6.Selected Financial Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Item 7.Managements Discussion and Analysis of Financial Condition and Results of Operations . . . . . . . . . . .29 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 Results of Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Liquidity and Capital Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Regulatory Matters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71 Accounting Matters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71 Effects of Inflation and Changing Prices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73 Item 7A. Quantitative and Qualitative Disclosures About Market Risk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 Item 8.Financial Statements and Supplementary Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80 Item 9.Changes in and Disagreements with Accountants on Accounting and Financial Disclosure . . . . . . . . . .177 Item 9A and Item 9A(T). Controls and Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .177 Item 9B.Other Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .178 PART III Item 10. Directors, Executive Officers, and Corporate Governance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 Item 11. Executive Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .178 Item 12. Security Ownership of Certain Beneficial Owners and Management and Related StockholderMatters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 Item 13. Certain Relationships and Related Transactions and Director Independence . . . . . . . . . . . . . . . . . . . . .179 Item 14. Principal Accountant Fees and Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .179 PART IV Item 15.Exhibits and Financial Statement Schedules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 SIGNATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 EXHIBIT INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .191This Form 10-K contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements should be read with the cautionary statements and important factors included on page 3 of this Form 10-K under the heading Forward-looking Statements. Forward-looking statements are all statements other than statements of historical fact, including those statements that are identified by the use of the words anticipates, estimates, expects, intends, plans, predicts, projects, and similar expressions. 24. GLOSSARY OF TERMS AND ABBREVIATIONS We use the words our, we or us with respect to certain information that relates to all Ameren Companies, as defined below. When appropriate, subsidiaries of Ameren are named specifically as we discuss their various business activities.AERG AmerenEnergy Resources Generating Company, a COLA Combined construction and operating license CILCO subsidiary that operates a non-rate-regulated electricapplication. generation business in Illinois.Cooling degree-days The summation of positive AFS Ameren Energy Fuels and Services Company, a differences between the mean daily temperature and a Resources Company subsidiary that procures fuel and 65-degree Fahrenheit base. This statistic is useful for natural gas and manages the related risks for the Amerenestimating electricity demand by residential and commercial Companies.customers for summer cooling. AITC Ameren Illinois Transmission Company, a wholly CT Combustion turbine electric generation equipment owned subsidiary of Ameren Corporation that is engaged in used primarily for peaking capacity. the construction and operation of transmission assets inDevelopment Company Ameren Energy Development Illinois and is regulated by the ICC. Company, which was an Ameren Energy Resources Ameren Ameren Corporation and its subsidiaries on a Company subsidiary and parent of Genco, Marketing consolidated basis. In references to financing activities,Company, AFS, and Medina Valley. It was eliminated in an acquisition activities, or liquidity arrangements, Ameren isinternal reorganization in February 2008. defined as Ameren Corporation, the parent.DOE Department of Energy, a U.S. government agency. Ameren Companies The individual registrants within theDRPlus Ameren Corporations dividend reinvestment and Ameren consolidated group.direct stock purchase plan. Ameren Illinois Utilities CIPS, IP and the rate-regulated Dth (dekatherm) one million Btus of natural gas. electric and gas utility operations of CILCO. EEI Electric Energy, Inc., an 80%-owned Ameren Ameren Services Ameren Services Company, an AmerenCorporation subsidiary that operates non-rate-regulated Corporation subsidiary that provides support services toelectric generation facilities and FERC-regulated Ameren and its subsidiaries.transmission facilities in Illinois. Prior to February 29, 2008, AMIL The balancing authority area operated by Ameren, EEI was 40% owned by UE and 40% owned by which includes the load of the Ameren Illinois Utilities andDevelopment Company. On February 29, 2008, UEs 40% the generating assets of AERG and Genco.ownership interest and Development Companys 40% AMMO The balancing authority area operated by Ameren, ownership interest were transferred to Resources which includes the load and generating assets of UE.Company. The remaining 20% is owned by Kentucky AMT Alternative minimum tax.Utilities Company. ARB Accounting Research Bulletin. EITF Emerging Issues Task Force, an organization ARO Asset retirement obligations. designed to assist the FASB in improving financial reporting Baseload The minimum amount of electric power through the identification, discussion and resolution of delivered or required over a given period of time at afinancial issues in keeping with existing authoritative steady rate.literature. Btu British thermal unit, a standard unit for measuring the ELPC Environmental Law and Policy Center. quantity of heat energy required to raise the temperature ofEPA Environmental Protection Agency, a U.S. one pound of water by one degree Fahrenheit.government agency. Capacity factor A percentage measure that indicates how Equivalent availability factor A measure that indicates much of an electric power generating units capacity wasthe percentage of time an electric power generating unit used during a specific period.was available for service during a period. CILCO Central Illinois Light Company, a CILCORP ERISA Employee Retirement Income Security Act of subsidiary that operates a rate-regulated electric1974, as amended. transmission and distribution business, a non-rate- Exchange Act Securities Exchange Act of 1934, as regulated electric generation business through AERG, and aamended. rate-regulated natural gas transmission and distributionFAC A fuel and purchased power cost recovery business, all in Illinois, as AmerenCILCO. CILCO owns all ofmechanism that allows UE to recover through customer the common stock of AERG. rates 95% of changes in fuel (coal, coal transportation, CILCORP CILCORP Inc., an Ameren Corporation natural gas for generation and nuclear) and purchased subsidiary that operates as a holding company for CILCO power costs, net of off-system revenues, including MISO and a non-rate-regulated subsidiary.costs and revenues, above or below the amount set in base CIPS Central Illinois Public Service Company, an Ameren rates. Corporation subsidiary that operates a rate-regulated FASB Financial Accounting Standards Board, a electric and natural gas transmission and distributionrulemaking organization that establishes financial business in Illinois as AmerenCIPS. accounting and reporting standards in the United States. CIPSCO CIPSCO Inc., the former parent of CIPS.FERC The Federal Energy Regulatory Commission, a U.S. CO2 Carbon dioxide. government agency.1 25. FIN FASB Interpretation. A FIN statement is anIP SPT Illinois Power Special Purpose Trust, which was explanation intended to clarify accounting pronouncements created as a subsidiary of IP LLC to issue TFNs as allowed previously issued by the FASB.under the Illinois Customer Choice Law. It was dissolved in Fitch Fitch Ratings, a credit rating agency.February 2009 because the remaining TFNs were redeemed FSP FASB Staff Position, a publication that providesby IP in September 2008. application guidance on FASB literature.IPA Illinois Power Agency, a state government agency FTRs Financial transmission rights, financial instruments that has broad authority to assist in the procurement of that entitle the holder to pay or receive compensation forelectric power for residential and nonresidential customers certain congestion-related transmission charges between beginning in June 2009. two designated points.ISRS Infrastructure system replacement surcharge. A Fuelco Fuelco LLC, a limited-liability company that cost recovery mechanism in Missouri that allows UE to provides nuclear fuel management and services to itsrecover gas infrastructure replacement costs from utility members. The members are UE, Luminant, and Pacific Gascustomers without a traditional rate case. and Electric Company. IUOE International Union of Operating Engineers, a labor GAAP Generally accepted accounting principles in theunion. United States of America. JDA The joint dispatch agreement among UE, CIPS, and Genco Ameren Energy Generating Company, a Resources Genco under which UE and Genco jointly dispatched electric Company subsidiary that operates a non-rate-regulated generation prior to its termination on December 31, 2006. electric generation business in Illinois and Missouri.Kilowatthour A measure of electricity consumption Gigawatthour One thousand megawatthours.equivalent to the use of 1,000 watts of power over a period Heating degree-days The summation of negative of one hour. differences between the mean daily temperature and a 65-Lehman Lehman Brothers Holdings, Inc. degree Fahrenheit base. This statistic is useful as anMACT Maximum Achievable Control Technology. indicator of demand for electricity and natural gas for winterMarketing Company Ameren Energy Marketing Company, space heating for residential and commercial customers. a Resources Company subsidiary that markets power for IBEW International Brotherhood of Electrical Workers, a Genco, AERG and EEI. labor union.Medina Valley AmerenEnergy Medina Valley Cogen ICC Illinois Commerce Commission, a state agency that L.L.C., a Resources Company subsidiary, which owns a regulates Illinois utility businesses, including the rate-40-megawatt gas-fired electric generation plant. regulated operations of CIPS, CILCO and IP. Megawatthour One thousand kilowatthours. Illinois Customer Choice Law Illinois Electric ServiceMGP Manufactured gas plant. Customer Choice and Rate Relief Law of 1997, whichMISO Midwest Independent Transmission System provided for electric utility restructuring and was designedOperator, Inc. to introduce competition into the retail supply of electric MISO Day Two Energy Market A market that uses energy in Illinois. market-based pricing, incorporating transmission Illinois electric settlement agreement A comprehensivecongestion and line losses, to compensate market settlement of issues in Illinois arising out of the end of tenparticipants for power. years of frozen electric rates, effective January 2, 2007. TheMissouri Environmental Authority Environmental Illinois electric settlement agreement, which becameImprovement and Energy Resources Authority of the state effective on August 28, 2007, was designed to avoid new of Missouri, a governmental body authorized to finance rate rollback and freeze legislation and legislation that would environmental projects by issuing tax-exempt bonds and impose a tax on electric generation in Illinois. Thenotes. settlement addresses the issue of power procurement, andMissouri Regulated A financial reporting segment it includes a comprehensive rate relief and customerconsisting of UEs rate-regulated businesses. assistance program. Money pool Borrowing agreements among Ameren and Illinois EPA Illinois Environmental Protection Agency, aits subsidiaries to coordinate and provide for certain short- state government agency.term cash and working capital requirements. Separate Illinois Regulated A financial reporting segmentmoney pools maintained for rate-regulated and non-rate- consisting of the regulated electric and natural gasregulated business are referred to as the utility money pool transmission and distribution businesses of CIPS, CILCO,and the non-state-regulated subsidiary money pool, IP and AITC.respectively. IP Illinois Power Company, an Ameren CorporationMoodys Moodys Investors Service Inc., a credit rating subsidiary. IP operates a rate-regulated electric and natural agency. gas transmission and distribution business in Illinois as MoPSC Missouri Public Service Commission, a state AmerenIP. agency that regulates Missouri utility businesses, including IP LLC Illinois Power Securitization Limited Liabilitythe rate-regulated operations of UE. Company, which was a special-purpose Delaware limited-MPS Multi-Pollutant Standard, an agreement reached in liability company. It was dissolved in February 2009 because2006 among Genco, CILCO (AERG), EEI and the Illinois the remaining TFNs, with respect to which this entity was EPA, which was codified in Illinois environmental created, were redeemed by IP in September 2008. regulations.2 26. MW Megawatt. IP were remitted to IP SPT. The designated funds were Native load Wholesale customers and end-use retail restricted for the sole purpose of making payments of customers, whom we are obligated to serve by statute,principal and interest on, and paying other fees and franchise, contract, or other regulatory requirement.expenses related to, the TFNs. Since the application of FIN NCF&O National Congress of Firemen and Oilers, a labor 46R, IP did not consolidate IP SPT. Therefore, the union. obligation to IP SPT appears on IPs balance sheet as of Non-rate-regulated Generation A financial reportingDecember 31, 2007. In September 2008, IP redeemed the segment consisting of the operations or activities of Genco, remaining TFNs. the CILCORP parent company, AERG, EEI, Medina Valley,TVA Tennessee Valley Authority, a public power and Marketing Company. authority. NOx Nitrogen oxide.UE Union Electric Company, an Ameren Corporation Noranda Noranda Aluminum, Inc. subsidiary that operates a rate-regulated electric generation, NRC Nuclear Regulatory Commission, a U.S. government transmission and distribution business, and a rate-regulated agency.natural gas transmission and distribution business in NYMEX New York Mercantile Exchange.Missouri as AmerenUE. NYSE New York Stock Exchange, Inc. OATT Open Access Transmission Tariff.FORWARD-LOOKING STATEMENTS OCI Other comprehensive income (loss) as defined by GAAP.Statements in this report not based on historical facts Off-system revenues Revenues from other than nativeare considered forward-looking and, accordingly, involve load sales.risks and uncertainties that could cause actual results to OTC Over-the-counter.differ materially from those discussed. Although such PGA Purchased Gas Adjustment tariffs, which allow theforward-looking statements have been made in good faith passing through of the actual cost of natural gas to utility and are based on reasonable assumptions, there is no customers. assurance that the expected results will be achieved. These PJM PJM Interconnection LLC. statements include (without limitation) statements as to PUHCA 2005 The Public Utility Holding Company Act of future expectations, beliefs, plans, strategies, objectives, 2005, enacted as part of the Energy Policy Act of 2005,events, conditions, and financial performance. In effective February 8, 2006.connection with the safe harbor provisions of the Private Regulatory lag Adjustments to retail electric and naturalSecurities Litigation Reform Act of 1995, we are providing gas rates are based on historic cost levels. Rate increase this cautionary statement to identify important factors that requests can take up to 11 months to be acted upon by thecould cause actual results to differ materially from those MoPSC and the ICC. As a result, revenue increasesanticipated. The following factors, in addition to those authorized by regulators will lag behind changing costs. discussed under Risk Factors and elsewhere in this report Resources Company Ameren Energy Resources Company, and in our other filings with the SEC, could cause actual LLC, an Ameren Corporation subsidiary that consists of results to differ materially from management expectations non-rate-regulated operations, including Genco, Marketingsuggested in such forward-looking statements: Company, EEI, AFS, and Medina Valley. It is the successor to regulatory or legislative actions, including changes in Ameren Energy Resources Company, which was eliminatedregulatory policies and ratemaking determinations and in an internal reorganization in February 2008.future rate proceedings or future legislative actions that RFP Request for proposal.seek to limit or reverse rate increases; RTO Regional Transmission Organization. uncertainty as to the continued effectiveness of the S&P Standard & Poors Ratings Services, a credit ratingIllinois power procurement process; agency that is a division of The McGraw-Hill Companies, changes in laws and other governmental actions, Inc.including monetary and fiscal policies; SEC Securities and Exchange Commission, a U.S. changes in laws or regulations that adversely affect the government agency.ability of electric distribution companies and other SERC SERC Reliability Corporation, one of the regionalpurchasers of wholesale electricity to pay their electric reliability councils organized for coordinating thesuppliers, including UE and Marketing Company; planning and operation of the nations bulk power supply. enactment of legislation taxing electric generators, in SFAS Statement of Financial Accounting Standards, theIllinois or elsewhere; accounting and financial reporting rules issued by the the effects of increased competition in the future due FASB.to, among other things, deregulation of certain aspects SO2 Sulfur dioxide.of our business at both the state and federal levels, and TFN Transitional Funding Trust Notes issued by IP SPT asthe implementation of deregulation, such as occurred allowed under the Illinois Customer Choice Law. IPwhen the electric rate freeze and power supply designated a portion of cash received from customercontracts expired in Illinois at the end of 2006; billings to pay the TFNs. The designated funds received by 3 27. increasing capital expenditure and operating expensegeneration plant construction, installation and requirements and our ability to recover these costs in aperformance, including costs associated with UEs timely fashion in light of regulatory lag;Taum Sauk pumped-storage hydroelectric plant the effects of participation in the MISO; incident and the plants future operation; the cost and availability of fuel such as coal, natural recoverability through insurance of costs associated gas, and enriched uranium used to produce electricity;with UEs Taum Sauk pumped-storage hydroelectric the cost and availability of purchased power and naturalplant incident; gas for distribution; and the level and volatility of futureoperation of UEs nuclear power facility, including market prices for such commodities, including the planned and unplanned outages, and decommissioning ability to recover the costs for such commodities;costs; the effectiveness of our risk management strategies the effects of strategic initiatives, including acquisitions and the use of financial and derivative instruments;and divestitures; prices for power in the Midwest, including forwardthe impact of current environmental regulations on prices; utilities and power generating companies and the business and economic conditions, including their expectation that more stringent requirements, including impact on interest rates, bad debt expense, and those related to greenhouse gases, will be introduced demand for our products;over time, which could have a negative financial effect; disruptions of the capital markets or other events that labor disputes, future wage and employee benefits make the Ameren Companies access to necessarycosts, including changes in discount rates and returns capital, including short-term credit, impossible, moreon benefit plan assets; difficult or costly;the inability of our counterparties and affiliates to meet our assessment of our liquidity;their obligations with respect to contracts, credit the impact of the adoption of new accounting standardsfacilities and financial instruments; and the application of appropriate technical accounting the cost and availability of transmission capacity for the rules and guidance; energy generated by the Ameren Companies facilities actions of credit rating agencies and the effects of such or required to satisfy energy sales made by the Ameren actions;Companies; weather conditions and other natural phenomena, legal and administrative proceedings; and including impacts to our customers; acts of sabotage, war, terrorism or intentionally the impact of system outages caused by severe disruptive acts. weather conditions or other events;Given these uncertainties, undue reliance should not be placed on these forward-looking statements. Except to the extent required by the federal securities laws, we undertake no obligation to update or revise publicly any forward-looking statements to reflect new information or future events.PART IITEM 1. BUSINESS. GENERALAmeren, headquartered in St. Louis, Missouri, is aThe following table presents our total employees at public utility holding company under PUHCA 2005December 31, 2008: administered by FERC. Ameren was formed in 1997 by theAmeren(a) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9,524 merger of UE and CIPSCO. Ameren acquired CILCORP inUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4,146 2003 and IP in 2004. Amerens primary assets are the CIPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 679 common stock of its subsidiaries, including UE, CIPS,Genco . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .577 Genco, CILCORP and IP. CILCORP/CILCO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .626IP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,173 Amerens subsidiaries are separate, independent legal entities with separate businesses, assets and liabilities. (a) Total for Ameren includes Ameren registrant and nonregistrant These subsidiaries operate rate-regulated electric subsidiaries. generation, transmission and distribution businesses, rate- As of January 1, 2009, the IBEW, the IUOE, the NCF&O regulated natural gas transmission and distributionand the Laborers and Gas Fitters labor unions collectively businesses, and non-rate-regulated electric generationrepresent about 58% of Amerens total employees. They businesses in Missouri and Illinois. Dividends on Amerensrepresent 63% of the employees at UE, 82% at CIPS, 70% common stock are dependent on distributions made to it byat Genco, 38% at CILCORP, 38% at CILCO, and 90% at IP. its subsidiaries.All collective bargaining agreements that expired in 2008have been renegotiated and ratified. Most of the collective 4 28. bargaining agreements have four- or five-year terms, andMissouri Regulated expire in 2011 and 2012. The collective bargaining Electric agreement between UE and IUOE Local 148, covering approximately 1,100 employees, expires on June 30, 2009. About 81% of UEs electric operating revenues were subject to regulation by the MoPSC in the year endedFor additional information about the development ofDecember 31, 2008. our businesses, our business operations, and factors affecting our operations and financial position, seeFollowing the expiration of a multiyear electric rate Managements Discussion and Analysis of Financial change moratorium, UE filed a request with the MoPSC in Condition and Results of Operations under Part II, Item 7,July 2006 for approval of an increase in its annual revenues of this report and Note 1 Summary of Significantfor electric service. In May 2007, the MoPSC issued an Accounting Policies to our financial statements under Partorder, that, as clarified, granted UE a $43 million increase in II, Item 8, of this report. base rates for electric service, effective June 4, 2007.On January 27, 2009, the MoPSC issued an order BUSINESS SEGMENTS responding to UEs April 2008 rate increase request, approving an increase for UE in annual revenues for electricAmeren has three reportable segments: Missouri service of approximately $162 million. The MoPSC also Regulated, Illinois Regulated, and Non-rate-regulated approved UEs implementation of a FAC and a vegetation Generation. CILCORP and CILCO have two reportable management and infrastructure inspection cost tracking segments: Illinois Regulated and Non-rate-regulated mechanism. Rate changes consistent with the MoPSC Generation. See Note 17 Segment Information to ourorder, as well as the FAC and the vegetation management financial statements under Part II, Item 8, of this report forand infrastructure inspection cost tracking mechanism, additional information on reporting segments. were effective as of March 1, 2009. These cost recovery and tracking mechanisms help to mitigate the negative effect of regulatory lag. RATES AND REGULATIONThe MoPSC initiated a proceeding in December 2008 Rates to develop revised rules for an environmental cost recovery mechanism, which has been authorized under Missouri law.Rates that UE, CIPS, CILCO and IP are allowed to Rules for the environmental cost recovery mechanism are charge for their utility services are an important influence expected to be approved by the MoPSC during the second upon their and Amerens consolidated results of operations, quarter of 2009 and will be effective once published in the financial position, and liquidity. The utility rates charged to Missouri Register. UE will not be able to implement an UE, CIPS, CILCO and IP customers are determined by environmental cost recovery mechanism until authorized by governmental entities. Decisions by these entities are the MoPSC as part of a rate case proceeding. UE has not influenced by many factors, including the cost of providing requested approval of an environmental cost recovery service, the quality of service, regulatory staff knowledge mechanism. and experience, economic conditions, public policy, and social and political views. Decisions made by these Gas governmental entities regarding rates, as well as the regulatory lag involved in filing and getting new ratesAll of UEs gas operating revenues were subject to approved, could have a material impact on the results ofregulation by the MoPSC in the year ended December 31, operations, financial position, or liquidity of UE, CIPS, 2008. CILCORP, CILCO, IP and Ameren.If certain criteria are met, UEs gas rates may beThe ICC regulates rates and other matters for CIPS,adjusted without a traditional rate proceeding. PGA clauses CILCO and IP. The MoPSC regulates rates and other permit prudently incurred natural gas costs to be passed matters for UE. The FERC regulates UE, CIPS, Genco, directly to the consumer. The ISRS also permits prudently CILCO, and IP as to their ability to charge market-basedincurred gas infrastructure replacement costs to be passed rates for the sale and transmission of energy in interstate directly to the consumer. commerce and various other matters discussed below As part of a 2007 stipulation and agreement approved under General Regulatory Matters. by the MoPSC authorizing an increase in annual natural gasAbout 35% of Amerens electric and 14% of its gasdelivery revenues of $6 million effective April 1, 2007, UE operating revenues were subject to regulation by theagreed not to file a natural gas delivery rate case before MoPSC in the year ended December 31, 2008. About 41%March 15, 2010. This agreement did not prevent UE from of Amerens electric and 86% of its gas operating revenuesfiling to recover gas infrastructure replacement costs were subject to regulation by the ICC in the year ended through an ISRS during this three-year rate moratorium. December 31, 2008. Wholesale revenues for UE, Genco and During 2008, the MoPSC approved two UE requests to AERG are subject to FERC regulation, but not subject to establish an ISRS to recover annual revenues of $2 million direct MoPSC or ICC regulation. in the aggregate, effective in March and November 2008.5 29. For further information on Missouri rate matters, seeIn September 2008, responding to CIPS, CILCOs and Results of Operations and Outlook in ManagementsIPs November 2007 electric and natural gas rate adjustment Discussion and Analysis of Financial Condition and Results requests, the ICC issued a consolidated order approving a of Operations under Part II, Item 7, Quantitative andnet increase in annual revenues for electric service of Qualitative Disclosures About Market Risk under Part II, $123 million in the aggregate (CIPS $22 million increase, Item 7A, and Note 2 Rate and Regulatory Matters, and CILCO $3 million decrease, and IP $104 million Note 15 Commitments and Contingencies to our financial increase) and a net increase in annual revenues for natural statements under Part II, Item 8, of this report.gas delivery service of $38 million in the aggregate (CIPS $7 million increase, CILCO $9 million decrease, and IP $40 million increase). Rate changes implementing these Illinois Regulatedadjustments were effective on October 1, 2008. The ICC alsoThe following table presents the approximateapproved an increase in the percentage of costs to be percentage of electric and gas operating revenues subject to recovered through fixed monthly charges for natural gas regulation by the ICC for each of the Illinois Regulated customers, as well as an increase in the Supply Cost companies for the year ended December 31, 2008:Adjustment factors for the customers who take their powersupply from the Ameren Illinois Utilities. These two rateElectric Gasstructure changes help to mitigate the negative effect of CIPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100% 100% regulatory lag. CILCORP/CILCO(a) . . . . . . . . . . . . . . . . . . . . . . . . .56100 For further information on Illinois rate matters, IP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100100including the pending court appeal of the September 2008consolidated electric and gas rate order, see Results of (a) AERGs revenues are not subject to ICC regulation.Operations and Outlook in Managements Discussion andIf certain criteria are met, CIPS, CILCOs and IPs gasAnalysis of Financial Condition and Results of Operations rates may be adjusted without a traditional rate proceeding. under Part II, Item 7, Quantitative and Qualitative PGA clauses permit prudently incurred natural gas costs to Disclosures About Market Risk under Part II, Item 7A, and be passed directly to the consumer.Note 2 Rate and Regulatory Matters, and Note 15 Commitments and Contingencies to our financial Environmental adjustment rate riders authorized by thestatements under Part II, Item 8, of this report. ICC permit the recovery of prudently incurred MGP remediation and litigation costs from CIPS, CILCOs and Non-rate-regulated Generation IPs Illinois electric and natural gas utility customers. In Non-rate-regulated Generation revenues are addition, IP has a tariff rider to recover the costs ofdetermined by market conditions. We expect the Non-rate- asbestos-related litigation claims, subject to the followingregulated Generation fleet of assets to have terms. Beginning in 2007, 90% of cash expenditures in6,480 megawatts of capacity available for the 2009 peak excess of the amount included in base electric rates isdemand. As discussed below, Genco, AERG, and EEI sell all recoverable by IP from a trust fund established by IP. Atof their power and capacity to Marketing Company via December 31, 2008, the trust fund balance was $23 million,power supply agreements. Marketing Company attempts to including accumulated interest. If cash expenditures areoptimize the value of those generation assets and mitigate less than the amount in base rates, IP will contribute 90%risks utilizing a variety of hedging techniques including of the difference to the fund. Once the trust fund iswholesale sales of capacity and energy, retail sales in the depleted, 90% of allowed cash expenditures in excess ofnon-rate-regulated Illinois market, spot market sales base rates will be recoverable through charges assessed toprimarily in MISO and PJM, and financial transactions. customers under the tariff rider.Marketing Company enters into long-term and short-term A multiyear electric rate moratorium expired and new contracts. Marketing Companys counterparties include electric rates for CIPS, CILCO and IP went into effect oncooperatives, municipalities, commercial and industrial January 2, 2007. The new rates reflected delivery servicecustomers, power marketers, MISO, and investor-owned tariffs approved by the ICC in November 2006 and a costutilities like the Ameren Illinois Utilities. See Note 14 recovery mechanism for power purchased on behalf of theRelated Party Transactions to our financial statements under Ameren Illinois Utilities customers. In 2007, an agreementPart II, Item 8, of this report for additional information, was reached among key stakeholders in Illinois to addressincluding Marketing Company sales to the Ameren Illinois the increase in electric rates and the future powerUtilities. procurement process. The Illinois electric settlementGeneral Regulatory Matters agreement provides $1 billion of funding from 2007 to 2010UE, CIPS, CILCO and IP must receive FERC approval to for rate relief for certain electric customers in Illinois,issue short-term debt securities and to conduct certain including $488 million to customers of the Ameren Illinoisacquisitions, mergers and consolidations involving electric Utilities. Amerens contributions over the four-year periodutility holding companies having a value in excess of under the Illinois electric settlement agreement aggregate$10 million. In addition, these Ameren utilities must receive $150 million. 6 30. authorization from the applicable state public utility are in material compliance with existing statutes and regulatory agency to issue stock and long-term debtregulations. securities (with maturities of more than 12 months) and to For additional discussion of environmental matters, conduct mergers, affiliate transactions, and various otherincluding NOx, SO2, and mercury emission reduction activities. Genco, AERG and EEI are subject to FERCsrequirements and the December 2005 breach of the upper jurisdiction when they issue any securities.reservoir at UEs Taum Sauk pumped-storage hydroelectricplant, see Liquidity and Capital Resources inUnder PUHCA 2005, FERC and any state public utilityManagements Discussion and Analysis of Financial regulatory agencies may access books and records ofCondition and Results of Operations under Part II, Item 7, Ameren and its subsidiaries that are determined to beand Note 15 Commitments and Contingencies to our relevant to costs incurred by Amerens rate-regulatedfinancial statements under Part II, Item 8, of this report. subsidiaries with respect to jurisdictional rates. PUHCA 2005 also permits Ameren, the ICC, or the MoPSC to request that FERC review cost allocations by AmerenSUPPLY FOR ELECTRIC POWER Services to other Ameren companies.Ameren operates an integrated transmission system Operation of UEs Callaway nuclear plant is subject to that comprises the transmission assets of UE, CIPS, CILCO, regulation by the NRC. Its facility operating license expiresIP and AITC. AITC placed its first transmission assets, on June 11, 2024. UE intends to submit a license extension jointly owned with IP, in service during the fourth quarter of application with the NRC to extend its Callaway nuclear2008. Any transmission assets of AITC would be eligible for plants operating license to 2044. UEs Osage hydroelectricrate recovery upon making the necessary filings with and plant and UEs Taum Sauk pumped-storage hydroelectricacceptance by FERC. Ameren also operates two balancing plant, as licensed projects under the Federal Power Act, are authority areas, AMMO (which includes UE) and AMIL subject to FERC regulations affecting, among other things, (which includes CIPS, CILCO, IP, AITC, Genco and AERG). the general operation and maintenance of the projects. The During 2008, the peak demand in AMMO was 8,644 MW license for UEs Osage hydroelectric plant expires onand in AMIL was 8,794 MW. The Ameren transmission March 30, 2047, and the license for UEs Taum Sauk plant system directly connects with 17 other balancing authority expires on June 30, 2010. In June 2008, UE filed anareas for the exchange of electric energy. application with FERC to relicense its Taum Sauk plant for UE, CIPS, CILCO and IP are transmission-owning another 40 years. The Taum Sauk plant is currently out ofmembers of MISO, and they have transferred functional service. It is being rebuilt due to a major breach of thecontrol of their systems to MISO. Transmission service on upper reservoir in December 2005. UEs Keokuk plant andthe UE, CIPS, CILCO and IP transmission systems is its dam, in the Mississippi River between Hamilton, Illinois,provided pursuant to the terms of the MISO OATT on file and Keokuk, Iowa, are operated under authority granted bywith FERC. EEI operates its own balancing authority area an Act of Congress in 1905.and its own transmission facilities in southern Illinois. TheFor additional information on regulatory matters, see EEI transmission system is directly connected to MISO and Note 2 Rate and Regulatory Matters and Note 15 TVA. EEIs generating units are dispatched separately from Commitments and Contingencies to our financial those of UE, Genco and AERG. statements under Part II, Item 8, of this report, which The Ameren Companies and EEI are members of include a discussion about the December 2005 breach ofSERC. SERC is responsible for the bulk electric power the upper reservoir at UEs Taum Sauk pumped-storagesupply system in much of the southeastern United States, hydroelectric plant.including all or portions of Missouri, Illinois, Arkansas,Kentucky, Tennessee, North Carolina, South Carolina, Environmental MattersGeorgia, Mississippi, Alabama, Louisiana, Virginia, Florida,Oklahoma, Iowa, and Texas. The Ameren membershipCertain of our operations are subject to federal, state,covers UE, CIPS, CILCO and IP. and local environmental statutes or regulations relating to the safety and health of personnel, the public, and the See Note 2 Rate and Regulatory Matters to our environment. These matters include identification, financial statements under Part II, Item 8, of this report for generation, storage, handling, transportation, disposal, further information. recordkeeping, labeling, reporting, and emergency response in connection with hazardous and toxic materials, safetyMissouri Regulated and health standards, and environmental protection requirements, including standards and limitations relating UEs electric supply is obtained primarily from its own to the discharge of air and water pollutants. Failure to generation. Factors that could cause UE to purchase power comply with those statutes or regulations could have include, among other things, absence of sufficient owned material adverse effects on us. We could be subject to generation, plant outages, the failure of suppliers to meet criminal or civil penalties by regulatory agencies. We could their power supply obligations, extreme weather conditions, be ordered to make payment to private parties by the and the availability of power at a cost lower than the cost of courts. Except as indicated in this report, we believe that we generating it. 7 31. In March 2006, UE completed the purchase of three CT As part of the Illinois electric settlement agreement facilities, totaling 1,490 megawatts of capacity, at a price of reached in 2007, the reverse power procurement auction $292 million. These purchases were designed to help meetprocess in Illinois was discontinued. It was replaced with a UEs increased generating capacity needs and to provide UEnew power procurement process led by the IPA beginning with additional flexibility in determining when to add future in 2009. Under the new plan, the IPA will procure separate baseload generating capacity. UE expects these CT facilitieswholesale products (capacity, energy swaps and renewable to satisfy demand growth until 2018 or 2020. However, due energy credits) on behalf of the Ameren Illinois Utilities for to the significant time required to plan, acquire permits for,the period of June 1, 2009, through May 30, 2014. The and build a baseload power plant, UE is actively studying products will be procured through a RFP process, which is future plant alternatives, including those that would use coalexpected to begin during the first half of 2009. In 2008, or nuclear fuel. In 2008, UE filed an integrated resource utilities contracted for necessary power and energy plan with the MoPSC. The plan included proposals to requirements not already supplied through the September pursue energy efficiency programs, expand the role of 2006 auction contracts, primarily through a RFP process renewable energy sources in UEs overall generation mix,that was subject to ICC review and approval. increase operational efficiency at existing power plants, and A portion of the electric power supply required for the possibly retire some generating units that are older and less Ameren Illinois Utilities to satisfy their distribution efficient.customers requirements is purchased from Marketing Company on behalf of Genco, AERG and EEI. Also as part of In July 2008, UE filed a COLA with the NRC for a the Illinois electric settlement agreement, the Ameren potential new nuclear unit at UEs existing Callaway County, Illinois Utilities entered into financial contracts with Missouri, nuclear plant site. In addition, in 2008, UE filed an Marketing Company (for the benefit of Genco and AERG), to application with the DOE for loan guarantees associated lock in energy prices for 400 to 1,000 megawatts annually with the potential construction of a new nuclear unit. UE of their round-the-clock power requirements during the has also signed contracts for certain long lead-time nuclear period June 1, 2008, to December 31, 2012, at relevant plant related equipment. The filing of the COLA and the DOE market prices at that time. These financial contracts do not loan guarantee application and entering into these contracts include capacity, are not load-following products, and do does not mean a decision has been made to build another not involve the physical delivery of energy. nuclear unit. These are only the first steps in the regulatorySee Note 2 Rate and Regulatory Matters and Note 14 licensing and procurement process and are necessary Related Party Transactions to our financial statements actions to preserve the option to develop a new nuclear under Part II, Item 8, of this report for additional unit. information on power procurement in Illinois.See also Outlook in Managements Discussion and Non-rate-regulated Generation Analysis of Financial Condition and Results of OperationsIn December 2006, Genco and Marketing Company, under Part II, Item 7 and Note 2 Rate and Regulatory and AERG and Marketing Company, entered into power Matters and Note 15 Commitments and Contingencies to supply agreements whereby Genco and AERG sell and our financial statements under Part II, Item 8, of this report. Marketing Company purchases all the capacity available from Gencos and AERGs generation fleets and the Illinois Regulatedassociated energy commencing on January 1, 2007. These power supply agreements continue through December 31,As of January 1, 2007, CIPS, CILCO and IP were 2022, and from year to year thereafter unless either party required to obtain all electric supply requirements for elects to terminate the agreement by providing the other customers who did not purchase electric supply from third- party with no less than six months advance written notice. party suppliers. The power procurement costs incurred by In December 2005, EEI and Marketing Company entered CIPS, CILCO and IP are passed directly to their customers into a power supply agreement whereby EEI sells all of its through a cost recovery mechanism. capacity and energy to Marketing Company commencing January 1, 2006. This agreement expires on December 31,In September 2006, a reverse power procurement 2015. All of Gencos, AERGs and EEIs generating capacity auction was held, as a result of which CIPS, CILCO and IP competes for the sale of energy and capacity in the entered into power supply contracts with the winning competitive energy markets through Marketing Company. bidders, including Marketing Company. Under these See Note 14 Related Party Transactions to our financial contracts, the electric suppliers are responsible for statements under Part II, Item 8, of this report for additional providing to CIPS, CILCO and IP energy, capacity, certain information. transmission, volumetric risk management, and other services necessary for the Ameren Illinois Utilities to serveFactors that could cause Marketing Company to the electric load needs of fixed price residential and smallpurchase power for the Non-rate-regulated Generation commercial customers (with less than one MW of demand)business segment include, among other things, absence of at an all-inclusive fixed price. These contracts commencedsufficient owned generation, plant outages, the failure of on January 1, 2007, with one-third of the supply contractssuppliers to meet their power supply obligations, and expiring in each of May 2008, 2009 and 2010.extreme weather conditions.8 32. FUEL FOR POWER GENERATION The following table presents the source of electric generation by fuel type, excluding purchased power, for the years ended December 31, 2008, 2007 and 2006: Coal Nuclear Natural Gas Hydroelectric Oil Ameren:(a)2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85% 12%1%2% (b)%2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8412 2 2(b)2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8513 1 1(b) Missouri Regulated: UE: 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77% 19%1%3% (b)% 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7619 2 3(b) 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7720 1 2(b) Non-rate-regulated Generation: Genco: 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99%-%1% -%(b)% 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 - 4- (b) 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 - 2-1 CILCO (AERG): 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99%-%1% -% -% 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 - 1- (b) 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 - 1- (b) EEI: 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100%-%-% -% -% 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100 - --- 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100 -(b) -- Total Non-rate-regulated Generation: 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99%-%1% -%(b)% 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 - 2- (b) 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 - 1- (b)(a) Includes amounts for Ameren registrant and nonregistrant subsidiaries and intercompany eliminations. (b) Less than 1% of total fuel supply. 9 33. The following table presents the cost of fuels for electric generation for the years ended December 31, 2008, 2007 and 2006:Cost of Fuels (Dollars per million Btus) 200820072006 Ameren: Coal(a)(d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 1.572 $ 1.399 $ 1.271 Nuclear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.493 0.490 0.434 Natural gas(b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10.503 7.939 8.718 Weighted average all fuels(c)(d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 1.573 $ 1.462 $ 1.281 Missouri Regulated: UE: Coal(a) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .