<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
COMPANY'S CONDENSED CONSOLIDATED FINANCIAL STATEMENTS INCLUDED IN ITS QUARTERLY
REPORT ON FORM 10-Q FOR THE QUARTERLY PERIOD ENDED MARCH 31, 1998 AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-END>                               MAR-31-1998
<CASH>                                          67,115
<SECURITIES>                                         0
<RECEIVABLES>                                  476,647<F1>
<ALLOWANCES>                                    22,142<F2>
<INVENTORY>                                     30,924
<CURRENT-ASSETS>                               631,079
<PP&E>                                       1,815,354
<DEPRECIATION>                                 652,637
<TOTAL-ASSETS>                               2,131,817
<CURRENT-LIABILITIES>                          373,440
<BONDS>                                        701,101
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                        11,017
<OTHER-SE>                                     865,382
<TOTAL-LIABILITY-AND-EQUITY>                 2,131,817
<SALES>                                        694,400
<TOTAL-REVENUES>                               697,427
<CGS>                                                0
<TOTAL-COSTS>                                  629,722
<OTHER-EXPENSES>                                23,118
<LOSS-PROVISION>                                     0<F3>
<INTEREST-EXPENSE>                              15,488
<INCOME-PRETAX>                                 29,099
<INCOME-TAX>                                    11,058
<INCOME-CONTINUING>                             18,041
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    18,041
<EPS-PRIMARY>                                     0.17
<EPS-DILUTED>                                     0.17
<FN>
<F1>EXCLUDES $23,060 OF LONG-TERM NOTES RECEIVABLE.
<F2>EXCLUDES $2,291 OF ALLOWANCE FOR DOUBTFUL LONG-TERM NOTES RECEIVABLE.
<F3>INCLUDED IN TOTAL COSTS AND EXPENSES LINE.
</FN>