Exhibit No. 12



COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES



The ratio of earnings to fixed charges is calculated using the Securities and Exchange Commission guidelines.



|                                                              |  |                         |     |      |   |      |  |      |     |  |      |     |  |  |   |    
|------------------------------------------------------------- |  | ----------------------- | --- | ---- | - | ---- |  | ---- | --- |  | ---- | --- |  |  | - | ---
|                                                              |  | Year Ended December 31,
|                                                              |  | 2006                    |     | 2005 |   | 2004 |  | 2003 |     |  | 2002
|                                                              |  | (dollars in millions)  
|Earnings as defined for fixed charges calculation             |  |                         |     |      |   |      |  |      |     |  |      |     |  |  |   |    
|Add:                                                          |  |                         |     |      |   |      |  |      |     |  |      |     |  |  |   |    
|Pretax income                                                 |  | $                       | 200 |      | $ | 325  |  | $    | 277 |  | $    | 234 |  |  | $ | 329
|Fixed charges                                                 |  |                         | 145 |      |   | 126  |  |      | 103 |  |      | 97  |  |  |   | 89 
|Deduct:                                                       |  |                         |     |      |   |      |  |      |     |  |      |     |  |  |   |    
|Interest capitalized(a)                                       |  |                         | 16  |      |   | 8    |  |      | 2   |  |      | 5   |  |  |   | 9  
|                                                              |  |                         |     |      |   |      |  |      |     |  |      |     |  |  |   |    
|Total earnings (as defined for the Fixed Charges calculation) |  | $                       | 329 |      | $ | 443  |  | $    | 378 |  | $    | 326 |  |  | $ | 409
|                                                              |  |                         |     |      |   |      |  |      |     |  |      |     |  |  |   |    
|Fixed charges:                                                |  |                         |     |      |   |      |  |      |     |  |      |     |  |  |   |    
|Interest on debt, including capitalized portions              |  | $                       | 138 |      | $ | 118  |  | $    | 93  |  | $    | 88  |  |  | $ | 82 
|Estimate of interest within rental expense                    |  |                         | 7   |      |   | 8    |  |      | 10  |  |      | 9   |  |  |   | 7  
|                                                              |  |                         |     |      |   |      |  |      |     |  |      |     |  |  |   |    
|Total fixed charges                                           |  | $                       | 145 |      | $ | 126  |  | $    | 103 |  | $    | 97  |  |  | $ | 89 
|                                                              |  |                         |     |      |   |      |  |      |     |  |      |     |  |  |   |    
|Ratio of earnings to fixed charges                            |  |                         | 2.3 |      |   | 3.5  |  |      | 3.7 |  |      | 3.4 |  |  |   | 4.6



|(a) | Excludes equity costs related to AFUDC that are included in Other Income and Expenses in the Consolidated Statements of Operations.
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