Exhibit 12.7

Illinois Power Company

Computation of Ratios of Earnings to Fixed Charges and Combined

Fixed Charges and Preferred Stock Dividend Requirements

(Thousands of Dollars, Except Ratios)



|                                                                                      |  |                         |         |      |   |         |  |   |         |   |      |   |         |  |   |        
|------------------------------------------------------------------------------------- |  | ----------------------- | ------- | ---- | - | ------- |  | - | ------- | - | ---- | - | ------- |  | - | -------
|                                                                                      |  | Year Ended December 31,
|                                                                                      |  | 2001                    |         | 2002 |   | 2003    |  |   | 2004(1) |   | 2005
|Net income from continuing operations                                                 |  | $                       | 168,473 |      | $ | 162,989 |  | $ | 117,113 |   |      | $ | 137,538 |  | $ | 97,039 
|Less- Change in accounting principle                                                  |  |                         | -       |      |   | -       |  |   | (2,294  | ) |      |   | -       |  |   | -      
|Add- Taxes based on income                                                            |  |                         | 117,221 |      |   | 104,209 |  |   | 76,023  |   |      |   | 87,591  |  |   | 65,171 
|                                                                                      |  |                         |         |      |   |         |  |   |         |   |      |   |         |  |   |        
|Net income before income taxes and change in accounting principle                     |  |                         | 285,694 |      |   | 267,198 |  |   | 195,430 |   |      |   | 225,129 |  |   | 162,210
|                                                                                      |  |                         |         |      |  
|Add- fixed charges:                                                                   |  |                         |         |      |   |         |  |   |         |   |      |   |         |  |   |        
|Interest on long term debt                                                            |  |                         | 104,861 |      |   | 94,738  |  |   | 146,045 |   |      |   | 112,616 |  |   | 41,028 
|Estimated interest cost within rental expense                                         |  |                         | 2,250   |      |   | 2,442   |  |   | 1,895   |   |      |   | 1,696   |  |   | 1,290  
|Amortization of net debt premium, discount, expenses and losses                       |  |                         | 18,638  |      |   | 18,135  |  |   | 17,751  |   |      |   | 18,772  |  |   | 2,315  
|                                                                                      |  |                         |         |      |   |         |  |   |         |   |      |   |         |  |   |        
|Total fixed charges                                                                   |  |                         | 125,749 |      |   | 115,315 |  |   | 165,691 |   |      |   | 133,084 |  |   | 44,633 
|                                                                                      |  |                         |         |      |   |         |  |   |         |   |      |   |         |  |   |        
|Earnings available for fixed charges                                                  |  |                         | 411,443 |      |   | 382,513 |  |   | 361,121 |   |      |   | 358,213 |  |   | 206,843
|                                                                                      |  |                         |         |      |   |         |  |   |         |   |      |   |         |  |   |        
|Ratio of earnings to fixed charges                                                    |  |                         | 3.27    |      |   | 3.31    |  |   | 2.17    |   |      |   | 2.69    |  |   | 4.63   
|                                                                                      |  |                         |         |      |   |         |  |   |         |   |      |   |         |  |   |        
|Earnings required for combined fixed charges and preferred stock dividends:           |  |                         |         |      |   |         |  |   |         |   |      |   |         |  |   |        
|Preferred stock dividends                                                             |  |                         | 2,294   |      |   | 2,294   |  |   | 2,294   |   |      |   | 2,294   |  |   | 2,294  
|Adjustment to pre-tax basis                                                           |  |                         | 1,597   |      |   | 1,466   |  |   | 1,434   |   |      |   | 1,461   |  |   | 1,542  
|                                                                                      |  |                         |         |      |   |         |  |   |         |   |      |   |         |  |   |        
|                                                                                      |  |                         | 3,891   |      |   | 3,760   |  |   | 3,728   |   |      |   | 3,755   |  |   | 3,836  
|                                                                                      |  |                         |         |      |   |         |  |   |         |   |      |   |         |  |   |        
|Combined fixed charges and preferred stock dividend requirements                      |  | $                       | 129,640 |      | $ | 119,075 |  | $ | 169,419 |   |      | $ | 136,839 |  | $ | 48,469 
|                                                                                      |  |                         |         |      |   |         |  |   |         |   |      |   |         |  |   |        
|Ratio of earnings to combined fixed charges and preferred stock dividend requirements |  |                         | 3.17    |      |   | 3.21    |  |   | 2.13    |   |      |   | 2.61    |  |   | 4.26   
|                                                                                      |  |                         |         |      |   |         |  |   |         |   |      |   |         |  |   |        



|(1) | Ameren Corporation purchased Illinois Power Company on September 30, 2004, amounts include combined predecessor and successor financial information.
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