8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported):

September 1, 2005

Commission File Number	Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number	IRS Employer Identification Number
1-14756	Ameren Corporation (Missouri Corporation) 1901 Chouteau Avenue St. Louis, Missouri 63103 (314) 621-3222	43-1723446
1-2967	Union Electric Company (Missouri Corporation) 1901 Chouteau Avenue St. Louis, Missouri 63103 (314) 621-3222	43-0559760
1-3672	Central Illinois Public Service Company (Illinois Corporation) 607 East Adams Street Springfield, Illinois 62739 (217) 523-3600	37-0211380
333-56594	Ameren Energy Generating Company (Illinois Corporation) 1901 Chouteau Avenue St. Louis, Missouri 63103 (314) 621-3222	37-1395586
2-95569	CILCORP Inc. (Illinois Corporation) 300 Liberty Street Peoria, Illinois 61602 (309) 677-5271	37-1169387

1-2732	Central Illinois Light Company (Illinois Corporation) 300 Liberty Street Peoria, Illinois 61602 (309) 677-5271	37-0211050
1-3004	Illinois Power Company (Illinois Corporation) 500 South 27th Street Decatur, Illinois 62521 (217) 424-6600	37-0344645

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

[ ] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

[ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

[ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

[ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

SECTION 8 - OTHER EVENTS

ITEM 8.01 Other Events.

Reference is made to Note 3 - Rate and Regulatory Matters under Part I, Item 1. Financial Statements and to Outlook under Part I, Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations of the combined Form 10-Q for the quarterly period ended June 30, 2005 of registrant Ameren Corporation (“Ameren”) and its registrant subsidiaries for a discussion of the February 2005 filing made by Central Illinois Public Service Company, doing business as AmerenCIPS (“CIPS”), Central Illinois Light Company, doing business as AmerenCILCO (“CILCO”) and Illinois Power Company, doing business as AmerenIP (“IP”) (collectively, the “Ameren Illinois Utilities”) with the Illinois Commerce Commission (“ICC”) for approval of a proposed reverse auction process for procuring electric generation and a proposed rate mechanism to pass generation costs through to customers, to take effect after the current Illinois electric rate freeze expires on January 1, 2007 and electric supply contracts expire on December 31, 2006. As reported in the Form 10-Q for the quarterly period ended June 30, 2005, the ICC in July 2005 denied the interlocutory administrative appeal by the Illinois Attorney General, the Citizens Utility Board (“CUB”) and the Environmental Law and Policy Center (“ELPC”) of the administrative law judge’s ruling which rejected their motion to dismiss the Ameren Illinois Utilities’ proposed generation procurement auction process. Also as reported in the Form 10-Q for the quarterly period ended June 30, 2005, the Ameren Illinois Utilities in July 2005 filed supplemental testimony which modified certain aspects of their February proposal to address issues raised by the ICC staff and certain other intervenors. In addition, the Form 10-Q for the quarterly period ended June 30, 2005 reported that in 2005, Ameren will begin the process of preparing utility cost-of-service studies to be submitted to the ICC as the basis for its determination of electric delivery service rates for the Ameren Illinois Utilities to be effective after the current rate freeze expires.

On September 1, 2005, the Illinois Attorney General, the Cook County State’s Attorney, the CUB and the ELPC filed a two-count complaint in the Chancery Division of the Circuit Court of Cook County, Illinois against the ICC and the individual ICC commissioners (the “Attorney General’s lawsuit”). The first count asks that the defendants be required to show by what authority the ICC claims it could approve market-based rates for electric service that has not been “declared competitive” pursuant to Section 16-113 of the Illinois Public Utilities Act (“PUA”). The second count seeks a declaratory judgment that the ICC lacks authority to approve market-based rates

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for electric service that has not been “declared competitive” pursuant to Section 16-113 of the PUA, and seeks injunctive relief prohibiting ICC approval of proposals by the Ameren Illinois Utilities and Commonwealth Edison Company that would impose market-based rates on customers who have electric service that has not been “declared competitive” pursuant to Section 16-113 of the PUA. The Ameren Illinois Utilities believe the claims are without merit and intend to vigorously oppose them. The legal argument underlying the Attorney General’s lawsuit is substantially similar to the legal argument presented to the administrative law judge, and to the ICC on interlocutory appeal, and rejected by both, in June and July 2005, respectively (as referred to above). On September 15, 2005, the Ameren Illinois Utilities filed their petition to intervene in the Attorney General’s lawsuit. If intervention is granted, the Ameren Illinois Utilities will deny the allegations in the complaint and seek a determination that the ICC has appropriate legal authority to approve the proposed electric generation procurement auction process pending before the ICC.

On September 2, 2005, Illinois Governor Blagojevich sent a letter to the ICC expressing his opposition to the Ameren Illinois Utilities’ proposed generation procurement auction process and requesting dismissal of the Ameren Illinois Utilities’ pending proceeding for approval of such process (“the Governor’s letter”). The Governor’s letter also stated his view that “the ICC is without authority to approve the market-based rates for the procurement of power, including the reverse auction, until this service [ to the various markets for electricity, especially the residential market, ] has been declared ‘competitive’.” A copy of the Governor’s letter is included as Exhibit 99.1. On September 15, 2005, the Ameren Illinois Utilities responded to the Governor’s letter. A copy of the Ameren Illinois Utilities’ letter is included as Exhibit 99.2.

The Ameren Illinois Utilities, which own virtually no generation, presently purchase energy and capacity under wholesale power supply contracts that expire on December 31, 2006. Through 2006, CIPS’ power supply is provided by its affiliate, Ameren Energy Generating Company, CILCO’s power supply is provided by its affiliate, AmerenEnergy Resources Generating Company and IP’s power supply is provided by non-affiliated companies. Accordingly, the Ameren Illinois Utilities will have to enter into new wholesale supply arrangements in order to satisfy their retail service obligations under the PUA beginning January 1, 2007. The effective date of new supply arrangements will coincide with the expiration of the retail rate freeze under the Illinois Electric Service Customer Choice and Rate Relief Law of 1997. The rate mechanism to pass generation costs through to customers as proposed in the Ameren Illinois Utilities’ February 2005 filing with the ICC would provide for full and timely recovery of costs incurred under the new power supply agreements. In addition, the Ameren Illinois Utilities intend to file revised tariffs with the ICC in late 2005 that would modify their electric delivery service rates effective January 2, 2007. Electric delivery service rates recover the Ameren Illinois Utilities’ transmission and distribution costs associated with the delivery of electric power and energy to their retail customers.

Both the Governor’s letter and the Attorney General’s lawsuit assert that the energy component of the Ameren Illinois Utilities’ retail rates for electricity should not be based on their cost to procure energy and capacity in the wholesale market. We are unable to predict the ultimate outcome of the Attorney General’s lawsuit or the pending ICC proceeding (as affected by the Governor’s letter), the timing of the final decisions on such matters or the impact on our results of operations, financial position, or liquidity. However, any decision or action that impairs the ability of the Ameren Illinois Utilities to fully recover purchased power costs from their electric customers in a timely manner could result in material adverse consequences. As noted in the Ameren Illinois Utilities’ response letter to the Illinois Governor (Exhibit 99.2 hereto), these consequences could include a significant drop in credit ratings (potentially to below investment grade status), a loss of access to the capital markets, higher borrowing costs, higher power supply costs, an inability to make timely energy infrastructure investments, reduced customer service, job losses and financial insolvency.

In light of efforts to limit the Ameren Illinois Utilities’ ability to recover their costs, Ameren and the Ameren Illinois Utilities are petitioning to intervene in the Attorney General’s lawsuit and if granted, will oppose the positions taken by the filing parties, and will vigorously defend the Ameren Illinois Utilities proposed generation procurement auction process in proceedings before the ICC, as well as complete their delivery service rate case filings by year end, and defend those positions in later hearings, in an effort to ensure full recovery of the Ameren Illinois Utilities’ costs and avoid or mitigate the potential material adverse consequences disclosed above. In addition, Ameren and the Ameren Illinois Utilities will continue to explore a number of legal and regulatory actions, strategies and alternatives to address these issues. There can be no assurance that Ameren and the Ameren Illinois Utilities will prevail in opposition to the Attorney General’s lawsuit, the stated opposition by the Illinois Governor and other stakeholders, or

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that the legal and regulatory actions, strategies and alternatives that Ameren and the Ameren Illinois Utilities are considering will be successful.

SECTION 9 - FINANCIALS STATEMENTS AND EXHIBITS

ITEM 9.01 Financial Statements and Exhibits.

(c) Exhibits

Exhibit Number    Title:

99.1       Illinois Governor’s Letter to the Commissioners of the ICC, dated September 2, 2005

99.2       Ameren Illinois Utilities’ Letter to the Illinois Governor, dated September 15, 2005

This combined Form 8-K is being filed separately 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 a “registrant”). Information contained herein relating to any individual registrant has been filed by such registrant on its own behalf. No registrant makes any representation as to information relating to any other registrant.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, each registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. The signature for each undersigned company shall be deemed to relate only to matters having reference to such company or its subsidiaries.

AMEREN CORPORATION (Registrant)
	/s/ Martin J. Lyons
	Martin J. Lyons
	Vice President and Controller (Principal Accounting Officer)

UNION ELECTRIC COMPANY (Registrant)
	/s/ Martin J. Lyons
	Martin J. Lyons
	Vice President and Controller (Principal Accounting Officer)

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CENTRAL ILLINOIS PUBLIC SERVICE COMPANY (Registrant)
	/s/ Martin J. Lyons
	Martin J. Lyons
	Vice President and Controller (Principal Accounting Officer)

AMEREN ENERGY GENERATING COMPANY (Registrant)
	/s/ Martin J. Lyons
	Martin J. Lyons
	Vice President and Controller (Principal Accounting Officer)

CILCORP INC. (Registrant)
	/s/ Martin J. Lyons
	Martin J. Lyons
	Vice President and Controller (Principal Accounting Officer)

CENTRAL ILLINOIS LIGHT COMPANY (Registrant)
	/s/ Martin J. Lyons
	Martin J. Lyons
	Vice President and Controller (Principal Accounting Officer)

ILLINOIS POWER COMPANY (Registrant)
	/s/ Martin J. Lyons
	Martin J. Lyons
	Vice President and Controller (Principal Accounting Officer)

Date:  September 15, 2005

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Exhibit Index

Exhibit Number:Title:

99.1        Illinois Governor’s Letter to the Commissioners of the ICC,

 dated September 2, 2005

99.2        Ameren Illinois Utilities’ Letter to the Illinois Governor,

      dated September 15, 2005

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EX-99.1

Exhibit 99.1

Office Of The Governor

207 STATE CAPITOL, SPRINGFIELD, ILLINOIS 62706

Rod R. Blagojevich

Governor

September 2, 2005

Dear Commissioners,

I have been closely following the developments of AmerenCILCO’s, AmerenCIPS’s, and AmerenIP’s (“Ameren’s”) proposal before the Illinois Commerce Commission (“ICC”)

to approve a procurement process (in this instance, a “reverse auction” has been proposed) that will result in the purchase of wholesale power at market-based prices

(consolidated docket numbers 05-0160, 05-0161, 05-0162). Please make this document available to all parties to this proceeding and make it a part of the record of the

consolidated dockets as the position of an interested party.

The road towards deregulation of the electric industry began in 1997 with amendments to the Public Utilities Act (“PUA”). Deregulation is based upon the predicate that

regulation is unnecessary in a competitive market. A competitive market will drive down retail rates and make regulation unnecessary. However, in 2001, this transition period

was extended because competition had not yet developed. To date, this competition has still not yet developed for most markets especially the market for residential ratepayers.

Therefore, the principles of deregulation have not been achieved.

The PUA only authorizes the Commission to approve market-based rates for customers who take electric service that has been declared “competitive” pursuant to Section 16-113

of the Act. Rate increases are unjustified and the ICC is without authority to approve the market-based rates for the procurement of power, including the reverse auction, until this

service has been declared “competitive.”

I appointed members of the Commission to protect the consumer. It is your job to ensure that rates remain just and reasonable, and to reject filings that circumvent the law or the

intention of the law. I consider an approval of a reverse auction procurement process of market-based rates for wholesale power either a serious neglect of duty or gross

incompetence by the ICC.

I will take whatever action is necessary to protect the public and ensure that the law is followed. Unless and until a competitive market develops, the request for higher rates

must be rejected.

Therefore, I urge you to uphold your duty to properly apply the law, protect Illinois consumers, and refuse to abandon the long-standing consumer protections provided by

the PUA. I request that you dismiss Ameren’s request for approval of the market-based rates of a reverse auction requested in the consolidated dockets 05-0160, 05-0161, and

05-0162 and any current or future filing authorizing a reverse auction or any similar procurement process. I urge you to declare that competition does not exist in the residential

market and therefore refuse to approve any retail rate filing or tariff that utilizes any such procurement process.

Sincerely,

 
/s/ Rod R. Blagojevich 

ROD R. BLAGOJEVICH

Governor 

EX-99.2

Exhibit 99.2

  September 15, 2005

The Honorable Rod R. Blagojevich

Governor

State of Illinois

James R. Thompson Center

100 W. Randolph, Floor 16

Chicago, IL 60601

Dear Governor Blagojevich:

The management of Central Illinois Light Company d/b/a AmerenCILCO, Central Illinois Public Service Company d/b/a AmerenCIPS and Illinois Power Company d/b/a AmerenIP (the "Ameren Illinois Utilities") read with great dismay your letter of September 2, 2005 to the members of the Illinois Commerce Commission ("ICC") in which you requested them to dismiss the Ameren Illinois Utilities' pending competitive procurement dockets, and stated your view that “the ICC is without authority to approve the market-based rates for the procurement of power, including the reverse auction, until this service [to the various markets for electricity, especially the residential market,] has been declared ‘competitive’”. In order to have a constructive dialogue around this important energy policy issue, we believe it is important that you have a complete understanding of our views regarding your request as it pertains to the law, the facts and sound regulatory and public policy matters. We remain willing to work with all stakeholders to fashion a means of addressing the impacts of the expiration of a decade-long rate reduction and rate freeze in a constructive manner, but we do not believe that the process is enhanced by a proposal that could result in a California-style meltdown in the Illinois electric sector.

At the outset, we believe it is important to point out that the ICC cannot validly dismiss the Ameren Illinois Utilities' pending proceeding without some basis in law, and it has already found, properly, that there is no legal basis for dismissing the case. Notably, the Ameren Illinois Utilities are obligated by law to provide electricity to their customers. Under the Ameren Illinois Utilities’ proposal, they will lawfully purchase this electricity from wholesale suppliers at a price determined by the competitive procurement auction, which amount represents their actual cost of procuring such electricity. The law requires that the Ameren Illinois Utilities be permitted to recover their actual cost of providing electric service to their customers.The ICC is bound to follow the law and issue a decision based on the substantial weight of the evidence. We strongly believe, as do many others participating in this

The Honorable Rod R. Blagojevich

September 15, 2005

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case, that the evidence will show that the Ameren Illinois Utilities' proposal is valid, workable and will produce the least-cost power for our customers.

We would also like to share several important facts with you. First, by 2007, our utilities will have experienced periods ranging from nearly 15 to 25 years during which their bundled electric rates have either not changed or declined. As a result, today the Ameren Illinois Utilities’ bundled residential electric rates are, on average, 17% below the national average. Given the significant increases in the cost of energy commodities, employee medical benefits and other operating costs during this time period, few utility companies in the country can make similar claims. These facts are, in large part, attributable to the success of deregulation in Illinois. Since the 1997 Restructuring Act was enacted, we estimate that our Illinois residential customers will have saved nearly $1 billion through 2006. However, over the past 15 to 25 years, our utilities have made substantial infrastructure investments and have experienced significant increases in operating costs. In order for our companies to continue to make the necessary infrastructure investments in our businesses going forward, as well as continue to provide well paying jobs and employee benefits for our workforce, we need to recover these additional costs in order to remain viable.

Second, the Ameren Illinois Utilities own virtually no generation and our existing supply contracts expire at the end of 2006. Accordingly, if the lights are to remain on come January, 2007, we need to purchase power somewhere, from someone. Last year, many stakeholders participated in numerous workshops to consider the best method for us to procure this power. The method that received most support, by far, was the reverse auction process. That process is fair, transparent, tested and will render the lowest cost power for customers. It will not boost our profits - we seek only to recover our costs of acquiring supply in the wholesale market - not a penny more and not a penny less.

Third, we cannot turn to affiliates for power supply at below-market prices. Our affiliates have only enough generation to supply about half of our Illinois distribution load, and cannot sell what they have to us at prices below market under Federal Energy Regulatory Commission standards. Moreover, by law, our distribution companies cannot subsidize a generator's operations, and a generator cannot be required to subsidize us.

Fourth, we believe it is important to recall that on two occasions in recent years, Ameren has purchased and essentially rescued two troubled Illinois utilities: AmerenCILCO, whose credit ratings were low investment grade, and whose service quality was the subject of an ICC investigation; and AmerenIP, which was saddled by overwhelming debt and a junk (below investment grade) status credit rating. We have restored AmerenCILCO’s credit ratings and service to a high level, and we have invested nearly a billion dollars in equity in AmerenIP to reduce its crushing debt, restore it to an investment grade credit rating status, protect Illinois jobs and end all

The Honorable Rod R. Blagojevich

September 15, 2005

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talk of bankruptcy. At the same time, we have meaningfully increased the level of energy infrastructure investments in these entities. We find it hard to believe that it is sound public policy to take several steps backwards in the rebuilding of these important Illinois companies.

Fifth, any action that impairs the ability of the Ameren Illinois Utilities to recover, in a timely fashion, our single largest cost - purchased power - could result in a host of adverse consequences. Those consequences include a significant drop in credit ratings (potentially to below investment grade status), a loss of access to the capital markets, and higher borrowing and power supply costs. As we learned in California (and with AmerenIP), suppliers sell power to a poor credit risk at a higher price than the price they will sell to a good credit risk. Other adverse consequences could include the inability to make timely energy infrastructure investments, reduced customer service, job losses and financial insolvency. As California learned, the hard way, consumers and taxpayers had to foot the bill. Certainly, this is not a road that the State of Illinois wishes to proceed down. No one wins.

Lastly, denying the Ameren Illinois Utilities full and timely recovery of our legitimately incurred power supply costs would be unlawful under the Constitutions of the United States and Illinois. This would needlessly create a number of legal issues, and potentially protracted litigation, that would not benefit stakeholders.

Governor Blagojevich, our objective all along has been to present a viable, long-term energy solution for our customers that produces the least cost option that is consistent with state and federal laws and reflects sound public, economic and regulatory policy. We are certain that you and other key stakeholders in the process share this objective. We look forward to engaging in further dialogue with you and other key stakeholders to find a constructive solution to this important matter.

  Sincerely,

cc: Senate President Emil Jones, Jr.

Speaker of the House Michael J. Madigan

ICC Chairman C. Edward Hurley

ICC Commissioner Kevin Wright

ICC Commissioner Lula Ford

ICC Commissioner Erin O'Connell-Diaz

ICC Commissioner Robert Lieberman