<ARTICLE> 5 <MULTIPLIER> 1,000 <PERIOD-TYPE> 9-MOS <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-START> JAN-01-1997 <PERIOD-END> SEP-30-1997 <CASH> 22,156 <SECURITIES> 0 <RECEIVABLES> 355,414 <ALLOWANCES> 10,040 <INVENTORY> 36,693 <CURRENT-ASSETS> 443,941 <PP&E> 1,759,020 <DEPRECIATION> 878,734 <TOTAL-ASSETS> 1,348,751 <CURRENT-LIABILITIES> 321,408 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 25,115 <OTHER-SE> 614,186 <TOTAL-LIABILITY-AND-EQUITY> 1,348,751 <SALES> 0 <TOTAL-REVENUES> 2,156,904 <CGS> 0 <TOTAL-COSTS> 0 <OTHER-EXPENSES> 1,985,702 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 23,522 <INCOME-PRETAX> 147,680 <INCOME-TAX> 58,400 <INCOME-CONTINUING> 89,280 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 89,280 <EPS-PRIMARY> 4.04 <EPS-DILUTED> 3.64