Ameren Corporation: Earnings Conference Call Announcement.

Business Editors

ST. LOUIS--(BUSINESS WIRE)--July 22, 2002

Ameren Corporation (NYSE:AEE) will conduct a conference call at 2 p.m. Central Standard Time on Thursday, July 25, 2002. Ameren President and COO Gary L. Rainwater and Senior Vice President-Finance Warner L. Baxter will discuss second-quarter financial results and other matters related to the company. Also on the call will be Ameren Controller Martin J. Lyons and Manager of Financial Communications and Investor Relations Bruce Steinke.

A 45-minute question-and-answer session will follow the senior management update. The call will be broadcast live on the Internet at http://www.ameren.com. The analyst call will also be available for replay on the Internet for five days.

To listen to the call, you can visit the web site or take advantage of a playback feature that will be available at 4 p.m., Central Standard Time, on July 25, and through Aug. 1. To playback, dial:

1-800-633-8284

The number to enter is 20762307

For international parties, the playback number to call is 402-977-9140; the number to enter is 20762307

BACKGROUND:

With assets of approximately $10 billion, Ameren operating companies serve 1.5 million electric customers and 300,000 natural gas customers in a 44,500-square mile area of Missouri and Illinois.