<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM CONDENSED
CONSOLIDATED BALANCE SHEETS, CONDENSED CONSOLIDATED STATEMENTS OF INCOME, AND
NOTES TO THE CONDENSED CONSOLIDATED FINANCIAL STATEMENTS AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH FORM 10-Q, JUNE 30, 2000.

<MULTIPLIER> 1,000

                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-2000
<PERIOD-START>                             JAN-01-2000
<PERIOD-END>                               JUN-30-2000
<CASH>                                          35,498
<SECURITIES>                                    28,575
<RECEIVABLES>                                  219,393
<ALLOWANCES>                                     2,121
<INVENTORY>                                     17,505
<CURRENT-ASSETS>                               367,710
<PP&E>                                         622,374
<DEPRECIATION>                                 371,606
<TOTAL-ASSETS>                                 662,050
<CURRENT-LIABILITIES>                          228,385
<BONDS>                                         64,238
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           273
<OTHER-SE>                                     340,831
<TOTAL-LIABILITY-AND-EQUITY>                   662,050
<SALES>                                        560,142
<TOTAL-REVENUES>                               560,142
<CGS>                                          484,094
<TOTAL-COSTS>                                  533,878
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               3,985
<INCOME-PRETAX>                                 31,638
<INCOME-TAX>                                    13,481
<INCOME-CONTINUING>                             18,157
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    18,157
<EPS-BASIC>                                       0.69
<EPS-DILUTED>                                     0.68