Ameren (AEE) 8-K Awards to Be Issued to Named Executive Officers

Exhibit 99.1

FORMULA FOR DETERMINING 2011 TARGET PERFORMANCE SHARE UNIT

AWARDS TO BE ISSUED TO NAMED EXECUTIVE OFFICERS

The target number of performance share units to be issued to each Named Executive Officer listed below for 2011 will be determined in accordance with the following formula:

2011 Target Number PSU Awards	=	Base Salary as of 1/1/11	x	Long-Term Incentive Target listed below
		Average closing price of Ameren Corporation Common Stock  on The New York Stock Exchange for each trading day in December 2010

NAMED EXECUTIVE OFFICER	LONG-TERM INCENTIVE TARGET AS PERCENT OF BASE SALARY
Voss		315	%
Lyons		175	%
Baxter		175	%
Sullivan		160	%
Naslund		150	%
Cisel		150	%