<ARTICLE>                     5
<MULTIPLIER>                  1,000
       
                             
<PERIOD-TYPE>                   12-MOS
<FISCAL-YEAR-END>                              DEC-31-1997
<PERIOD-START>                                 Jan-01-1997
<PERIOD-END>                                   DEC-31-1997
<CASH>                                         228,688
<SECURITIES>                                   176,834
<RECEIVABLES>                                  190,594
<ALLOWANCES>                                   0
<INVENTORY>                                    105,514
<CURRENT-ASSETS>                               718,375
<PP&E>                                         3,059,596
<DEPRECIATION>                                 1,505,067
<TOTAL-ASSETS>                                 2,745,798
<CURRENT-LIABILITIES>                          194,651
<BONDS>                                        757,100
<PREFERRED-MANDATORY>                          0
<PREFERRED>                                    25,465
<COMMON>                                       44,928
<OTHER-SE>                                     1,083,772
<TOTAL-LIABILITY-AND-EQUITY>                   2,745,798
<SALES>                                        1,484,503
<TOTAL-REVENUES>                               1,484,503
<CGS>                                          1,106,811
<TOTAL-COSTS>                                  1,276,635
<OTHER-EXPENSES>                               (21,303)
<LOSS-PROVISION>                               0
<INTEREST-EXPENSE>                             67,488
<INCOME-PRETAX>                                89,483
<INCOME-TAX>                                   33,109
<INCOME-CONTINUING>                            53,691
<DISCONTINUED>                                 0
<EXTRAORDINARY>                                0
<CHANGES>                                      0
<NET-INCOME>                                   53,691
<EPS-PRIMARY>                                  $1.26<F1>
<EPS-DILUTED>                                  $1.25
        
<FN>
<F1> EPS-BASIC
</FN>