<ARTICLE> 5
<LEGEND>
This schedule contains summary financial information extracted from SEC Form
10-Q and is qualified in its entirety by reference to such financial statements.
</LEGEND>
<MULTIPLIER> 1000
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-END>                               JUN-30-1997
<CASH>                                          23,869
<SECURITIES>                                         0
<RECEIVABLES>                                  156,445
<ALLOWANCES>                                     2,368
<INVENTORY>                                    116,618
<CURRENT-ASSETS>                               340,910
<PP&E>                                       1,525,440
<DEPRECIATION>                                 408,118
<TOTAL-ASSETS>                               1,625,392
<CURRENT-LIABILITIES>                          283,136
<BONDS>                                        376,865
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           415
<OTHER-SE>                                     732,159
<TOTAL-LIABILITY-AND-EQUITY>                 1,625,392
<SALES>                                        468,064
<TOTAL-REVENUES>                               468,064
<CGS>                                          409,163
<TOTAL-COSTS>                                  409,163
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               1,256
<INCOME-PRETAX>                                  5,226
<INCOME-TAX>                                     2,248
<INCOME-CONTINUING>                                976
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                       976
<EPS-PRIMARY>                                     0.02
<EPS-DILUTED>                                     0.02