<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
COMPANY'S BALANCE SHEET AT MARCH 31, 1997, JUNE 30, 1997 AND SEPTEMBER 30, 1997
AND INCOME STATEMENTS FOR THE PERIODS ENDED MARCH 31, 1997, JUNE 30, 1997 AND
SEPTEMBER 30, 1997 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS AND THEIR RELATED FOOTNOTES.  THIS SCHEDULE IS A
RESTATEMENT OF SCHEDULES FROM PREVIOUS FILINGS TO INCORPORATE THE PROVISIONS OF
SFAS NO. 128 - EARNINGS PER SHARE.

</LEGEND>
<MULTIPLIER> 1,000,000
       
                                               
<PERIOD-TYPE>                 3-MOS          6-MOS          9-MOS
<FISCAL-YEAR-END>         DEC-31-1997   DEC-31-1997      DEC-31-1997
<PERIOD-END>              MAR-31-1997   JUN-30-1997      SEP-30-1997
<CASH>                          1,385         1,280              991
<SECURITIES>                      421           447              573
<RECEIVABLES>                   3,778         3,488            3,509
<ALLOWANCES>                       60            52               45
<INVENTORY>                     1,335         1,458            1,409
<CURRENT-ASSETS>                7,701         7,425            7,241
<PP&E>                         47,451        48,172           48,941
<DEPRECIATION>                 25,767        26,127           26,564
<TOTAL-ASSETS>                 34,917        34,957           35,471
<CURRENT-LIABILITIES>           8,352         8,270            7,325
<BONDS>                         3,918         3,553            4,464
<COMMON>                        1,069         1,069            1,069
<PREFERRED-MANDATORY>               0             0                0
<PREFERRED>                         0             0                0
<OTHER-SE>                     15,074        15,477           15,984
<TOTAL-LIABILITY-AND-EQUITY>   34,917        34,957           35,471
<SALES>                        10,794        20,741           30,871
<TOTAL-REVENUES>               11,093        21,367           31,695
<CGS>                               0             0                0
<TOTAL-COSTS>                   9,634        18,512           27,591
<OTHER-EXPENSES>                    0             0                0
<LOSS-PROVISION>                    0             0                0
<INTEREST-EXPENSE>                 82           158              227
<INCOME-PRETAX>                 1,459         2,855            4,104
<INCOME-TAX>                      628         1,201            1,723
<INCOME-CONTINUING>               831         1,654            2,381
<DISCONTINUED>                      0             0                0
<EXTRAORDINARY>                     0             0                0
<CHANGES>                           0             0                0
<NET-INCOME>                      831         1,654            2,381
<EPS-PRIMARY>                    1.27          2.53             3.64
<EPS-DILUTED>                    1.27          2.52             3.62