EXHIBIT 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,
|                                                              |  | 2008                    |     | 2007 |   | 2006 |  | 2005 |     | 2004
|                                                              |  | (dollars in millions)  
|Earnings as defined for fixed charges calculation             |  |                         |     |      |   |      |  |      |     |      |   |     |  |   |    
|Add:                                                          |  |                         |     |      |   |      |  |      |     |      |   |     |  |   |    
|Pretax income                                                 |  | $                       | 408 |      | $ | 386  |  | $    | 200 |      | $ | 325 |  | $ | 277
|Fixed charges                                                 |  |                         | 140 |      |   | 130  |  |      | 145 |      |   | 126 |  |   | 103
|Deduct:                                                       |  |                         |     |      |   |      |  |      |     |      |   |     |  |   |    
|Interest capitalized(a)                                       |  |                         | 10  |      |   | 11   |  |      | 16  |      |   | 8   |  |   | 2  
|                                                              |  |                         |     |      |   |      |  |      |     |      |   |     |  |   |    
|Total earnings (as defined for the Fixed Charges calculation) |  | $                       | 538 |      | $ | 505  |  | $    | 329 |      | $ | 443 |  | $ | 378
|                                                              |  |                         |     |      |   |      |  |      |     |      |   |     |  |   |    
|Fixed charges:                                                |  |                         |     |      |   |      |  |      |     |      |   |     |  |   |    
|Interest on debt, including capitalized portions              |  | $                       | 133 |      | $ | 120  |  | $    | 138 |      | $ | 118 |  | $ | 93 
|Estimate of interest within rental expense                    |  |                         | 7   |      |   | 10   |  |      | 7   |      |   | 8   |  |   | 10 
|                                                              |  |                         |     |      |   |      |  |      |     |      |   |     |  |   |    
|Total fixed charges                                           |  | $                       | 140 |      | $ | 130  |  | $    | 145 |      | $ | 126 |  | $ | 103
|                                                              |  |                         |     |      |   |      |  |      |     |      |   |     |  |   |    
|Ratio of earnings to fixed charges                            |  |                         | 3.8 |      |   | 3.9  |  |      | 2.3 |      |   | 3.5 |  |   | 3.7



|(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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