<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONDENSED STATEMENT OF INCOME FOR THE NINE MONTHS ENDED SEPTEMBER 30, 1999 AND
THE CONDENSED BALANCE SHEET AT SEPTEMBER 30, 1999 AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000

                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-START>                             JAN-01-1999
<PERIOD-END>                               SEP-30-1999
<CASH>                                               0
<SECURITIES>                                         0
<RECEIVABLES>                                  147,339
<ALLOWANCES>                                     7,261
<INVENTORY>                                        868
<CURRENT-ASSETS>                               170,903
<PP&E>                                       1,859,115
<DEPRECIATION>                               1,002,900
<TOTAL-ASSETS>                               1,041,223
<CURRENT-LIABILITIES>                          280,434
<BONDS>                                        164,311
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                       191,968
<OTHER-SE>                                     218,532
<TOTAL-LIABILITY-AND-EQUITY>                 1,041,223
<SALES>                                              0
<TOTAL-REVENUES>                               494,739
<CGS>                                                0
<TOTAL-COSTS>                                  376,997
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              12,301
<INCOME-PRETAX>                                106,078
<INCOME-TAX>                                    43,528
<INCOME-CONTINUING>                             62,550
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    62,550
<EPS-BASIC>                                          0
<EPS-DILUTED>                                        0