<ARTICLE> 5 <LEGEND> THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE COMPANY'S BALANCE SHEET AT SEPTEMBER 30, 1997 AND INCOME STATEMENT FOR THE NINE MONTH PERIOD ENDED SEPTEMBER 30, 1997 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS AND THEIR RELATED FOOTNOTES. </LEGEND> <MULTIPLIER> 1,000,000 <PERIOD-TYPE> 9-MOS <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-END> SEP-30-1997 <CASH> 991 <SECURITIES> 573 <RECEIVABLES> 3,509 <ALLOWANCES> 45 <INVENTORY> 1,409 <CURRENT-ASSETS> 7,241 <PP&E> 48,941 <DEPRECIATION> 26,564 <TOTAL-ASSETS> 35,471 <CURRENT-LIABILITIES> 7,325 <BONDS> 4,464 <COMMON> 1,069 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <OTHER-SE> 15,984 <TOTAL-LIABILITY-AND-EQUITY> 35,471 <SALES> 30,871 <TOTAL-REVENUES> 31,695 <CGS> 0 <TOTAL-COSTS> 27,591 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 227 <INCOME-PRETAX> 4,104 <INCOME-TAX> 1,723 <INCOME-CONTINUING> 2,381 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 2,381 <EPS-PRIMARY> 3.64 <EPS-DILUTED> 3.64