<ARTICLE>                                             5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED BALANCE SHEET AND CONSOLIDATED STATEMENT OF OPERATIONS AND RETAINED
EARNINGS AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS.
</LEGEND>
<MULTIPLIER>  1000
       
                                                 

<PERIOD-TYPE>                                     6-MOS
<FISCAL-YEAR-END>                           DEC-31-1997
<PERIOD-END>                                JUN-30-1997
<CASH>                                            90625
<SECURITIES>                                      34829
<RECEIVABLES>                                    244917
<ALLOWANCES>                                       3271
<INVENTORY>                                           0
<CURRENT-ASSETS>                                 514780
<PP&E>                                           289019
<DEPRECIATION>                                   159008
<TOTAL-ASSETS>                                   824448
<CURRENT-LIABILITIES>                            405255
<BONDS>                                           23464
<PREFERRED-MANDATORY>                                 0
<PREFERRED>                                           0
<COMMON>                                          17731
<OTHER-SE>                                       309130
<TOTAL-LIABILITY-AND-EQUITY>                     824448
<SALES>                                               0
<TOTAL-REVENUES>                                 635783
<CGS>                                                 0
<TOTAL-COSTS>                                    597599
<OTHER-EXPENSES>                                  16334
<LOSS-PROVISION>                                      0
<INTEREST-EXPENSE>                                  872
<INCOME-PRETAX>                                   22855
<INCOME-TAX>                                       7805
<INCOME-CONTINUING>                               15050
<DISCONTINUED>                                        0
<EXTRAORDINARY>                                       0
<CHANGES>                                             0
<NET-INCOME>                                      15050
<EPS-PRIMARY>                                      1.17
<EPS-DILUTED>                                      1.17