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): June 13, 2012

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
1-3672	Ameren Illinois Company (Illinois Corporation) 300 Liberty Street Peoria, Illinois 61602 (309) 677-5271	37-0211380

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.

On June 13, 2012, Ameren Corporation (“Ameren”) issued a press release announcing the officer changes described under Item 8.01 below.

A copy of the press release is furnished with this Form 8-K and attached hereto as Exhibit 99.1. Exhibit 99.1 shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities under that section and shall not be deemed to be incorporated by reference into any filing of Ameren under the Securities Act of 1933, as amended, or the Exchange Act.

ITEM 8.01 Other Events.

On June 13, 2012, Ameren announced that Scott A. Cisel, Chairman, President and Chief Executive Officer of Ameren Illinois Company, doing business as Ameren Illinois (“Ameren Illinois”), has left Ameren to pursue other interests. Effective immediately, Richard J. Mark, most recently the Senior Vice President, Customer Operations, of Union Electric Company, doing business as Ameren Missouri, assumed the positions of Chairman, President and Chief Executive Officer of Ameren Illinois, effective June 13, 2012.

ITEM 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit Number	Title
99.1	Press release, dated June 13, 2012.

This combined Form 8-K is being filed separately by Ameren Corporation and Ameren Illinois 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.

- 2 -

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 thereunto 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, Jr.

Martin J. Lyons, Jr.

Senior Vice President and Chief Financial Officer

AMEREN ILLINOIS COMPANY

(Registrant)

/s/ Martin J. Lyons, Jr.

Martin J. Lyons, Jr.

Senior Vice President and Chief Financial Officer

Date: June 13, 2012

EX-99.1

EXHIBIT 99.1

NEWS RELEASE

1901 Chouteau Avenue : St. Louis, MO 63103 : Ameren.com

Contacts Corporate media Brian Bretsch 314.554.4135 bbretsch@ameren.com Illinois media Leigh Morris 217.535.5228 lmorris@ameren.com Analysts Doug Fischer 314.554.4859 dfischer@ameren.com

For Immediate Release

Ameren announces promotion of Richard J. Mark to Chairman, President and CEO of Ameren Illinois Company

St. Louis, June 13, 2012 – Ameren Corporation (NYSE:AEE) announced today, that effective immediately, Richard J. Mark is promoted to chairman, president and chief executive officer of Ameren Illinois Company, an electric and gas delivery utility subsidiary of Ameren Corporation. Mark replaces Scott A. Cisel who has left the company to pursue other interests.

Mark, who was senior vice president, Customer Operations, Ameren Missouri, joined Ameren in 2002. “Richard brings a strong operations background to Ameren Illinois,” said Thomas R. Voss, chairman, president and CEO of Ameren. “He is very active in the community and he is attuned to customers’ desires for safe, reliable and affordable energy. His background and experience align very well with Ameren Illinois’ mission. I’m confident Richard will execute Ameren Illinois’ infrastructure investment commitments and will continue to enhance customer satisfaction.”

Replacing Mark as leader of Customer Operations for Ameren Missouri will be Michael L. Moehn. Moehn will transfer from a similar role at Ameren Illinois and become senior vice president of Customer Operations, Ameren Missouri. Moehn has held many leadership positions since joining Ameren in 2000 after a successful career in public accounting at PricewaterhouseCoopers LLP. Until January 2012, Moehn was senior vice president of Corporate Planning where he led Ameren’s strategic planning and risk management efforts. “Moving Michael into a senior leadership role at Ameren Missouri will allow us to leverage his broad experience and skills at the operations level at Ameren Missouri,” Voss added.

With assets of more than $23 billion, St. Louis-based Ameren Corporation owns a diverse mix of electric generating plants strategically located in our Midwest market, with a generating capacity of nearly 16,000 megawatts. Through our Missouri and Illinois subsidiaries, we serve 2.4 million electric customers and more than 900,000 natural gas customers in a 64,000-square-mile area. Our mission is to meet their energy needs in a safe, reliable, efficient and environmentally responsible manner. For more information, visit Ameren.com.

# # #