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 8, 2009

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

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))

ITEM 7.01        Regulation FD Disclosure.

The common stock offering announced by Ameren Corporation (“Ameren”) which is described under Item 8.01 of this Form 8-K was not reflected in Ameren’s earnings guidance, issued and effective August 6, 2009.  Ameren currently estimates that the common stock offering is expected to produce dilution of approximately $0.05 per share (approximately $0.06 per share if the green shoe is exercised in full) in 2009.

ITEM 8.01        Other Events.

On September 8, 2009, Ameren announced its plan to offer 19,000,000 shares of its common stock and to grant the underwriters an option for a period of 30 days to purchase up to an additional 2,850,000 shares of its common stock.  The offering is subject to market conditions.  Ameren’s press release related thereto is attached as Exhibit 99.1.

ITEM 9.01        Financial Statements and Exhibits.

(d)           Exhibits

Exhibit Number:	Title:
99.1	Press release regarding Ameren’s intention to offer common stock,
	issued on September 8, 2009.

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Forward-Looking Statements

Statements in this report not based on historical facts are considered “forward-looking” and, accordingly, involve risks and uncertainties that could cause actual results to differ materially from those discussed.  Although such forward-looking statements have been made in good faith and are based on reasonable assumptions, there is no assurance that the expected results will be achieved.  These statements include (without limitation) statements as to future expectations, beliefs, plans, strategies, objectives, events, conditions, and financial performance.  In connection with the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995, we are providing this cautionary statement to identify important factors that could cause actual results to differ materially from those anticipated.  The following factors, in addition to those discussed elsewhere in this release and in our filings with the Securities and Exchange Commission, could cause actual results to differ materially from management expectations suggested in such forward-looking statements:

·   regulatory or legislative actions, including changes in regulatory policies and ratemaking determinations, such as the outcome of pending Union Electric Company, doing business as AmerenUE (“UE”), Central Illinois Public Service Company, doing business as AmerenCIPS, Central Illinois Light Company, doing business as AmerenCILCO, and Illinois Power Company, doing business as AmerenIP, rate proceedings, and future rate proceedings or future legislative actions that seek to limit or reverse rate increases;

·   uncertainty as to the continued effectiveness of the Illinois power procurement process;

·   changes in laws and other governmental actions, including monetary and fiscal policies;

·   changes in laws or regulations that adversely affect the ability of electric distribution companies and other purchasers of wholesale electricity to pay their suppliers, including UE and Ameren Energy Marketing Company;

·   enactment of legislation taxing electric generators, in Illinois or elsewhere;

·   the effects of increased competition in the future due to, among other things, deregulation of certain aspects of our business at both the state and federal levels, and the implementation of deregulation, such as occurred when the electric rate freeze and power supply contracts expired in Illinois at the end of 2006;

·   increasing capital expenditure and operating expense requirements and our ability to recover these costs in a

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timely fashion in light of regulatory lag;

·   the effects of participation in the Midwest Independent System Operator, Inc.;

·   the cost and availability of fuel such as coal, natural gas, and enriched uranium used to produce electricity; the cost and availability of purchased power and natural gas for distribution; and the level and volatility of future market prices for such commodities, including the ability to recover the costs for such commodities;

·   the effectiveness of our risk management strategies and the use of financial and derivative instruments;

·   prices for power in the Midwest, including forward prices;

·   business and economic conditions, including their impact on interest rates, bad debt expense, and demand for our products;

·   disruptions of the capital markets or other events that make the Ameren companies’ access to necessary capital, including short-term credit and liquidity, impossible, more difficult or more costly;

·   our assessment of our liquidity;

·   the impact of the adoption of new accounting standards and the application of appropriate technical accounting rules and guidance;

·   actions of credit rating agencies and the effects of such actions;

·   the impact of weather conditions and other natural phenomena on us and our customers;

·   the impact of system outages caused by severe weather conditions or other events;

·   generation plant construction, installation and performance, including costs associated with UE’s Taum Sauk pumped-storage hydroelectric plant incident and the plant’s future operation;

·   impairments of long-lived assets or goodwill;

·   the recovery of costs associated with UE’s Taum Sauk pumped-storage hydroelectric plant incident and investment in a combined nuclear plant construction and operating licensing application for a second unit at its Callaway nuclear plant;

·   operation of UE’s nuclear power facility, including planned and unplanned outages, and decommissioning costs;

·   the effects of strategic initiatives, including acquisitions and divestitures;

·   the impact of current environmental regulations on utilities and power generating companies and the expectation that more stringent requirements, including those related to greenhouse gases, will be enacted over time, which could limit the operation of our generating units or otherwise have a negative financial effect;

·   labor disputes, future wage and employee benefits costs, including changes in discount rates and returns on benefit plan assets;

·   the inability of our counterparties and affiliates to meet their obligations with respect to contracts, credit facilities and financial instruments;

·   the cost and availability of transmission capacity for the energy generated by the Ameren companies’ facilities or required to satisfy energy sales made by the Ameren companies;

·   legal and administrative proceedings; and

·   acts of sabotage, war, terrorism or intentionally disruptive acts.

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.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

AMEREN CORPORATION

(Registrant)

 /s/ Martin J. Lyons                                                                                              

Martin J. Lyons

Senior Vice President and Chief Financial Officer

Date:  September 8, 2009

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Exhibit Index

Exhibit Number:	Title:
99.1	Press release regarding Ameren’s intention to offer common stock,
	issued on September 8, 2009.

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EX-99.1

Exhibit 99.1

Media	Analysts	Investors
Susan Gallagher	Doug Fischer	Investor Services
(314) 554-2175	(314) 554-4859	(800) 255-2237
sgallagher@ameren.com	dfischer@ameren.com	invest@ameren.com

FOR IMMEDIATE RELEASE

Ameren Corporation Announces Intention to Offer Common Stock

ST. LOUIS, Sept. 8, 2009 -- Ameren Corporation (NYSE: AEE) announced today its plan to offer 19,000,000 shares of its common stock and to grant the underwriters an option for a period of 30 days to purchase up to an additional 2,850,000 shares of its common stock. The offering is subject to market conditions. Ameren expects to use the net proceeds from the issuance of the common stock to make investments in its rate-regulated utility subsidiaries in the form of equity capital contributions and for general corporate purposes. The joint book-running managers for the offering are Barclays Capital Inc., J.P. Morgan Securities Inc., BofA Merrill Lynch, Morgan Stanley & Co. Incorporated and UBS Securities LLC.

This press release does not constitute an offer to sell or the solicitation of an offer to buy any securities in any jurisdiction to any person to whom it is unlawful to make such offer or solicitation in such jurisdiction. The offering may be made by means of a prospectus and a related prospectus supplement, copies of which may be obtained when available from Barclays Capital Inc., c/o Broadridge Integrated Distribution Services, 1155 Long Island Avenue, Edgewood, New York 11717, telephone: (888) 603-5847, fax: (631) 254-7140 or by e-mail at Barclaysprospectus@broadridge.com; J.P. Morgan Securities Inc., 4 Chase Metrotech Center, CS Level, Brooklyn, New York 11245, telephone: (718) 242-8002 or fax: (718) 242-8003; BofA Merrill Lynch, 4 World Financial Center, New York, New York 10080, Attention: Prospectus Department; Morgan Stanley & Co. Incorporated, 180 Varick Street, 2nd Floor, New York, New York 10014, telephone (866) 718-1649; and UBS Securities LLC, Prospectus Department, 299 Park Avenue, New York, New York 10171, Attention: Clint Lauriston, telephone (877) 827-6444, ext. 561-3884.

With assets of approximately $23 billion, Ameren serves approximately 2.4 million electric customers and almost one million natural gas customers in a 64,000-square-mile area of Missouri and Illinois. Ameren owns a diverse mix of electric generating plants strategically located in its Midwest market with a generating capacity of more than 16,400 megawatts.

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