News Releases

Gary L. Rainwater, chairman, president and chief executive officer of Ameren Corporation (NYSE: AEE), announced today that Senior Vice President-Generation Thomas R. Voss has been promoted to executive vice president and chief operating officer of Ameren Corporation. Voss, long a member of the Ameren senior management team, has directed generation operations since 2003 and for more than 30 years served in Energy Delivery, leading that organization from 1999 to 2003. With this promotion, he assumes the added responsibility for all Energy Delivery operations across Illinois and Missouri.

Vice President for Government Policy and Consumer Affairs Richard J. Mark has been promoted to senior vice president of AmerenUE Energy Delivery. In that role, Mark will be responsible for the electric and natural gas distribution and customer service operations for AmerenUE in Missouri. Mark's government and public policy responsibilities will be assumed by Steven R. Sullivan, Ameren senior vice president, general counsel and secretary.

Mark will report to Voss, as will Scott A. Cisel, the president of AmerenCILCO, AmerenCIPS and AmerenIP (the Illinois Energy Delivery business lines); Senior Vice President of Generation R. Alan Kelley; Senior Vice President Energy Delivery David A. Whiteley; President of AmerenEnergy Marketing Andy Serri; and President of AmerenEnergy Fuels & Services Michael G. Mueller.

Rainwater also announced the promotion of Charles D. Naslund, vice president, Nuclear Operations, to senior vice president and chief nuclear officer. He replaces Garry L. Randolph who is retiring. Naslund reports to Rainwater. All these officers will assume their new positions effective Jan. 1, 2005.

With assets of $18 billion, Ameren, through its subsidiaries, serves 2.3 million electric customers and 900,000 natural gas customers in a 64,000 square- mile area of Missouri and Illinois.

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