EXHIBIT 12-1

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES
(Thousands of Dollars)

|                                                    |                          |   |                     |         |                     |   |                     |         |  |   |         |         | 
|--------------------------------------------------- | ------------------------ | - | ------------------- | ------- | ------------------- | - | ------------------- | ------- |  | - | ------- | ------- | 
|                                                    |                          |   | Twelve Months Ended |         | Twelve Months Ended |   | Twelve Months Ended
|                                                    |                          |   | December 31, 1999   |         | December 31, 1998   |   | December 31, 1997  
|                                                    |                          |   |                     |         |                     |   |                    
|EARNINGS AS DEFINED (1)                            
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|Pre-tax income                                      |                          | $ | 162,389             |         |                     | $ | 114,619             |         |  | $ | 125,630 |        
|                                                   
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|Fixed charges                                       |                          |   | 59,340              |         |                     |   | 61,304              |         |  |   | 57,905  |        
|                                                    |                          |   |                     |         |                     |   |                     |         |  |   |         |        
|                                                    | Earnings as defined      |   | $                   | 221,729 |                     |   | $                   | 175,923 |  |   | $       | 183,535 | 
|                                                    |                          |   |                     |         |                     |   |                     |         |  |   |         |        
|FIXED CHARGES AS DEFINED (1)                       
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|Interest on long-term debt                          |                          | $ | 48,455              |         |                     | $ | 47,091              |         |  | $ | 47,024  |        
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|Interest on other borrowed funds                    |                          |   | 8,626               |         |                     |   | 12,113              |         |  |   | 8,664   |        
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|Amortization of debt discounts, premium
and expense |                          |   | 1,144               |         |                     |   | 955                 |         |  |   | 1,032   |        
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|Interest implicit in rentals (2)                    |                          |   | 1,115               |         |                     |   | 1,145               |         |  |   | 1,185   |        
|                                                    |                          |   |                     |         |                     |   |                     |         |  |   |         |        
|                                                    | Fixed charges as defined |   | $                   | 59,340  |                     |   | $                   | 61,304  |  |   | $       | 57,905  | 
|                                                    |                          |   |                     |         |                     |   |                     |         |  |   |         |        
|Ratio of Earnings to Fixed Charges                  |                          |   | 3.74                |         |                     |   | 2.87                |         |  |   | 3.17    |        
|                                                    |                          |   |                     |         |                     |   |                     |         |  |   |         |        



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|Notes: |  |                                                                                                   
|------ |  | --------------------------------------------------------------------------------------------------
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|(1)    |  | Earnings and fixed charges are defined and computed in accordance with Item
503 of Regulation S-K.
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|(2)    |  | This amount is estimated to be a reasonable approximation of the interest
portion of rentals.     

MichCon is a guarantor of certain other debt. Fixed charges related to such debt
are deemed to be immaterial and therefore have been excluded from the above
ratios.