Company Update

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): January 23, 2015 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) 6 Executive Drive Collinsville, Illinois 62234 (618) 343-8150 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 8.01 Other Events. On January 23, 2015, Ameren Illinois Company (“AIC”) filed a request with the Illinois Commerce Commission (“ICC”) seeking approval to increase its natural gas delivery service rates by $53 million annually. The natural gas rate increase request is based on a 10.25 percent return on equity, a capital structure composed of 50% equity, a rate base of $1.2 billion, and a test year ended December 31, 2016. The ICC proceedings relating to the proposed natural gas delivery service rate changes will take place over a period of up to 11 months, with a decision by the ICC required by December 2015 and new rates expected to be effective in January 2016. AIC cannot predict the level of any natural gas delivery service rate change that the ICC may approve, when any rate change may go into effect, or whether any rate increase that may eventually be approved will be sufficient for AIC to recover its costs and earn a reasonable return on its investments when such increase goes into effect. 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. 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) By: /s/ Martin J. Lyons, Jr. Name: Martin J. Lyons, Jr. Title: Executive Vice President and Chief Financial Officer AMEREN ILLINOIS COMPANY (Registrant) By: /s/ Richard J. Mark Name: Richard J. Mark Title: Chairman and President Date: January 23, 2015