WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.

  


<ARTICLE> 5
<MULTIPLIER> 1,000
       
                                                                                            
<PERIOD-TYPE>                   12-MOS                   9-MOS                   6-MOS                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1997             DEC-31-1997             DEC-31-1997
<PERIOD-START>                             JAN-01-1997             JAN-01-1997             JAN-01-1997             JAN-01-1997
<PERIOD-END>                               DEC-31-1997             SEP-30-1997             JUN-30-1997             MAR-31-1997
<CASH>                                          91,154                 130,570                 186,957                 299,727
<SECURITIES>                                         0                       0                       0                       0
<RECEIVABLES>                                  993,098                 636,840                 520,339                 673,636
<ALLOWANCES>                                         0                       0                       0                       0
<INVENTORY>                                    937,949               1,108,311                 993,253                 996,254
<CURRENT-ASSETS>                             2,203,632               2,073,667               1,841,999               2,081,255
<PP&E>                                      12,621,635              12,224,761              12,090,972              11,847,685
<DEPRECIATION>                               7,430,841               7,215,181               7,114,764               7,023,692
<TOTAL-ASSETS>                               7,934,619               7,637,904               7,347,805               7,378,855
<CURRENT-LIABILITIES>                        1,739,851               1,570,805               1,572,379               1,571,453
<BONDS>                                      1,975,281               1,780,468               1,493,771               1,504,665
<PREFERRED-MANDATORY>                                0                       0                       0                       0
<PREFERRED>                                          0                       0                       0                       0
<COMMON>                                        91,451                  91,675                  91,739                  92,806
<OTHER-SE>                                   3,124,248               3,198,176               3,214,263               3,226,163
<TOTAL-LIABILITY-AND-EQUITY>                 7,934,619               7,637,904               7,347,805               7,378,855
<SALES>                                      8,233,723               6,115,368               4,230,790               2,396,830
<TOTAL-REVENUES>                             8,340,046               6,196,219               4,294,922               2,416,098
<CGS>                                        6,301,046               4,612,195               3,233,837               1,872,074
<TOTAL-COSTS>                                6,301,046               4,612,195               3,233,837               1,872,074
<OTHER-EXPENSES>                                     0                       0                       0                       0
<LOSS-PROVISION>                                     0                       0                       0                       0
<INTEREST-EXPENSE>                             136,149                 101,226                  67,407                  33,652
<INCOME-PRETAX>                                126,585                 227,951                 190,999                 114,798
<INCOME-TAX>                                   119,085                 159,027                 144,754                 110,210
<INCOME-CONTINUING>                              7,500                  68,924                  46,245                   4,588
<DISCONTINUED>                                       0                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0                       0
<CHANGES>                                            0                       0                       0                       0
<NET-INCOME>                                     7,500                  68,924                  46,245                   4,588
<EPS-PRIMARY><BASIC>                               .08                     .75                     .50                     .05
<EPS-DILUTED>                                      .08                     .75                     .50                     .05