<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
COMPANY'S SEC FORM 10-Q FOR THE PERIOD ENDING SEPTEMBER 30, 1996 AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1996
<PERIOD-END>                               SEP-30-1996
<CASH>                                          14,886
<SECURITIES>                                         0
<RECEIVABLES>                                   88,722
<ALLOWANCES>                                        77
<INVENTORY>                                     41,240
<CURRENT-ASSETS>                               187,188
<PP&E>                                       3,000,443
<DEPRECIATION>                               1,457,187
<TOTAL-ASSETS>                               1,850,690
<CURRENT-LIABILITIES>                          218,272
<BONDS>                                        627,442
<PREFERRED-MANDATORY>                            4,391
<PREFERRED>                                          0
<COMMON>                                             0
<OTHER-SE>                                     508,381
<TOTAL-LIABILITY-AND-EQUITY>                 1,850,690
<SALES>                                        708,654
<TOTAL-REVENUES>                               732,879
<CGS>                                          242,338
<TOTAL-COSTS>                                  413,465
<OTHER-EXPENSES>                                33,299
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              20,092
<INCOME-PRETAX>                                266,023
<INCOME-TAX>                                   154,104
<INCOME-CONTINUING>                            111,919
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   111,919
<EPS-PRIMARY>                                     1.28
<EPS-DILUTED>                                        0