<TABLE> <S> <C>

<PAGE>

<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM CONDENSED
CONSOLIDATED FINANCIAL STATEMENTS FOR THE PERIOD ENDING JUNE 30, 1998 AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1998             DEC-31-1998
<PERIOD-START>                             APR-01-1998             JAN-01-1998
<PERIOD-END>                               JUN-30-1998             JUN-30-1998
<CASH>                                          13,938                  13,938
<SECURITIES>                                         0                       0
<RECEIVABLES>                                   85,938                  85,938
<ALLOWANCES>                                         0                       0
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                               178,279                 178,279
<PP&E>                                         124,043                 124,043
<DEPRECIATION>                                       0                       0
<TOTAL-ASSETS>                               1,078,129               1,078,129
<CURRENT-LIABILITIES>                           55,365                  55,365
<BONDS>                                        531,596                 531,596
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          2                       2
<COMMON>                                           538                     538
<OTHER-SE>                                     342,121                 342,121
<TOTAL-LIABILITY-AND-EQUITY>                 1,078,129               1,078,129
<SALES>                                              0                       0
<TOTAL-REVENUES>                               109,713                 196,965
<CGS>                                                0                       0
<TOTAL-COSTS>                                        0                       0
<OTHER-EXPENSES>                                41,506                  83,948
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                               8,867                  19,827
<INCOME-PRETAX>                                 36,575                  47,326
<INCOME-TAX>                                    15,313                  20,229
<INCOME-CONTINUING>                             21,262                  27,097
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                    808                  10,777
<CHANGES>                                            0                       0
<NET-INCOME>                                    20,454                  16,320
<EPS-PRIMARY>                                     0.37                    0.29
<EPS-DILUTED>                                     0.37                    0.29
        

</TABLE>