EX-99.1 4 dex991.htm FORMULA FOR DETERMINING 2010 TARGET PERFORMANCE SHARE UNIT AWARDS Formula for Determining 2010 Target Performance Share Unit Awards

Exhibit 99.1

FORMULA FOR DETERMINING 2010 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 2010 will be determined in accordance with the following formula:

 

2010

Target Number

PSU

Awards

  

=

 

 

   

Base Salary

as of 1/1/10

    x   

Long-Term

Incentive Target

listed below

   x    .9    
     Average closing price of Ameren Corporation Common Stock on The New York Stock Exchange for each trading day in December 2009

 

NAMED EXECUTIVE OFFICER

    LONG -TERM INCENTIVE
TARGET AS PERCENT OF BASE SALARY
Voss    315%
Lyons    160%
Baxter    180%
Sullivan    180%
Naslund    180%