Common use of Performance Grid Clause in Contracts

Performance Grid. The number of Performance Share Units earned by the Participant under this Agreement will be determined in accordance with the following grid. If the actual performance results fall between two of the categories listed below, straight-line interpolation will be used to determine the amount earned. Payouts that otherwise would have been more than 100% of Target will be capped at Target if the Company’s total shareholder return (“TSR”) is negative over the three-year period. TSR shall be calculated in the manner set forth in Exhibit 1 hereto and compared to the peer group identified in Exhibit 1. Ameren’s Percentile in Total Shareholder Return vs. Utility Peers During the Performance Period Payout—Percent of Target Performance Share Units Granted 90th percentile + 200% 70th percentile 150% 50th percentile 100% 30th percentile 50% <30th percentile but three-year average GAAP Earnings Per Share (“EPS”)1 reaches or exceeds the average of the Executive Incentive Plan (“EIP”) threshold levels for 2012, 2013 and 2014 30% <30th percentile and three-year average GAAP EPS1 does not reach the average of the EIP threshold levels for 2012, 2013 and 2014 0% (no payout)

Performance Grid. The number of Performance Share Units earned by the Participant under this Agreement will be determined in accordance with the following grid. If the actual performance results fall between two of the categories listed below, straight-line interpolation will be used to determine the amount earned. Payouts that otherwise would have been more than 100% of Target will be capped at Target if the Company’s total shareholder return (“TSR”) is negative over the three-year period. TSR shall be calculated in the manner set forth in Exhibit 1 hereto and compared to the peer group identified in Exhibit 1. Ameren’s Percentile in Total Shareholder Return vs. Utility Peers During the Performance Period Payout—Percent of Target Performance Share Units Granted 90th percentile + 200200 % 70th percentile 150150 % 50th percentile 100100 % 30th percentile 5050 % <30th percentile but threeThree-year average GAAP Year Average Earnings Per Share (“EPS”)1 reaches or exceeds the average of the Executive Incentive Plan (“EIP”) EIP threshold levels for 2012in 2011, 2012 and 2013 and 2014 3030 % <30th percentile and threeThree-year average GAAP EPS1 Year Average Earnings Per Share does not reach the average of the EIP threshold levels for 2012in 2011, 2012 and 2013 and 2014 0% (no payout)

Performance Grid. The number of Performance Share Units earned by the Participant under this Agreement will be determined in accordance with the following grid. If the actual performance results fall between two of the categories listed below, straight-line interpolation will be used to determine the amount earned. Payouts that otherwise would have been more than 100% of Target will be capped at Target if the Company’s total shareholder return (“TSR”) is negative over the three-year period. TSR shall be calculated in the manner set forth in Exhibit 1 hereto and compared to the peer group identified in Exhibit 1. Ameren’s Percentile in Total Shareholder Return vs. Utility Peers During the Performance Period Payout—Percent of Target Performance Share Units Granted 90th percentile + 200% 70th percentile 150% 50th percentile 100% 30th percentile 50% <30th percentile but three-year average GAAP Earnings Per Share (“EPS”)1 reaches or exceeds the average of the Executive Incentive Plan (“EIP”) threshold levels for 20122013, 2013 2014 and 2014 2015 30% <30th percentile and three-year average GAAP EPS1 does not reach the average of the EIP threshold levels for 20122013, 2013 2014 and 2014 2015 0% (no payout)

Performance Grid. The number of Performance Share Units earned by the Participant under this Agreement will be determined in accordance with the following grid. If the actual performance results fall between two of the categories listed below, straight-line interpolation will be used to determine the amount earned. Payouts that otherwise would have been more than 100% of Target will be capped at Target if the Company’s total shareholder return (“TSR”) is negative over the three-year period. TSR shall be calculated in the manner set forth in Exhibit 1 hereto and compared to the peer group identified in Exhibit 1. Ameren’s Percentile in Total Shareholder Return vs. Utility Peers During the Performance Period Payout—Percent of Target Performance Share Units Granted 90th percentile + 200% 70th percentile 150% 50th percentile 100% 30th percentile 50% <30th percentile but threeThree-year average GAAP Year Average Earnings Per Share (“EPS”)1 reaches or exceeds the average of the Executive Incentive Plan (“EIP”) EIP threshold levels for 2012in 2010, 2013 2011 and 2014 2012 30% <30th percentile and threeThree-year average GAAP EPS1 Year Average Earnings Per Share does not reach the average of the EIP threshold levels for 2012in 2010, 2013 2011 and 2014 2012 0% (no payout)