<ARTICLE> 5
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>               DEC-31-1998
<PERIOD-START>                  JAN-01-1998
<PERIOD-END>                    MAR-31-1998
<CASH>                                22,166
<SECURITIES>                               0
<RECEIVABLES>                        330,411
<ALLOWANCES>                          10,290
<INVENTORY>                           39,387
<CURRENT-ASSETS>                     420,827
<PP&E>                             1,877,563
<DEPRECIATION>                       955,483
<TOTAL-ASSETS>                     1,369,453
<CURRENT-LIABILITIES>                294,344
<BONDS>                              248,993
<PREFERRED-MANDATORY>                      0
<PREFERRED>                                0
<COMMON>                              50,682
<OTHER-SE>                           654,736
<TOTAL-LIABILITY-AND-EQUITY>       1,369,453
<SALES>                                    0
<TOTAL-REVENUES>                     750,193
<CGS>                                      0
<TOTAL-COSTS>                        692,657
<OTHER-EXPENSES>                           0
<LOSS-PROVISION>                           0
<INTEREST-EXPENSE>                     3,916
<INCOME-PRETAX>                       53,620
<INCOME-TAX>                          21,260
<INCOME-CONTINUING>                   32,360
<DISCONTINUED>                             0
<EXTRAORDINARY>                            0
<CHANGES>                                  0
<NET-INCOME>                          32,360
<EPS-PRIMARY>                           0.65<F1>
<EPS-DILUTED>                           0.63<F2>
<FN>
<F1>EARNINGS PER SHARE - BASIC (IN COMPLIANCE WITH SFAS 128)
<F2>EARNINGS PER SHARE - DILUTED (IN COMPLIANCE WITH SFAS 128)
</FN>