<ARTICLE> 5
<CIK> 0000006769
<NAME> ART. 5 FDS FOR THIRD QUARTER 10-Q
<MULTIPLIER> 1,000
<CURRENCY> U.S. DOLLAR
       
                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1996
<PERIOD-START>                             JAN-01-1996
<PERIOD-END>                               SEP-30-1996
<EXCHANGE-RATE>                                  1,000
<CASH>                                          13,235
<SECURITIES>                                         0
<RECEIVABLES>                                  182,810
<ALLOWANCES>                                         0
<INVENTORY>                                     15,687
<CURRENT-ASSETS>                               234,498
<PP&E>                                       5,198,527
<DEPRECIATION>                               2,198,674
<TOTAL-ASSETS>                               3,297,259
<CURRENT-LIABILITIES>                          256,881
<BONDS>                                      1,225,794
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                       113,748
<OTHER-SE>                                   1,361,085
<TOTAL-LIABILITY-AND-EQUITY>                 3,297,259
<SALES>                                        670,869
<TOTAL-REVENUES>                               672,510
<CGS>                                          485,438
<TOTAL-COSTS>                                  485,438
<OTHER-EXPENSES>                                26,049
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              44,994
<INCOME-PRETAX>                                116,029
<INCOME-TAX>                                    45,800
<INCOME-CONTINUING>                             70,229
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    70,229
<EPS-PRIMARY>                                      .83
<EPS-DILUTED>                                      .83