<TABLE> <S> <C>

<ARTICLE>                                        UT
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED BALANCE SHEETS, CONSOLIDATED STATEMENTS OF INCOME AND CONSOLIDATED
STATEMENTS OF CASH FLOWS AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER>                                                           1,000
       
<S>                                                       <C>
<FISCAL-YEAR-END>                                         DEC-31-1997
<PERIOD-START>                                            JAN-01-1997
<PERIOD-END>                                              JUN-30-1997
<PERIOD-TYPE>                                             6-MOS
<BOOK-VALUE>                                              PER-BOOK
<TOTAL-NET-UTILITY-PLANT>                                          3,744,580
<OTHER-PROPERTY-AND-INVEST>                                                0
<TOTAL-CURRENT-ASSETS>                                               326,365
<TOTAL-DEFERRED-CHARGES>                                             671,212
<OTHER-ASSETS>                                                        98,302
<TOTAL-ASSETS>                                                     4,840,459
<COMMON>                                                             762,136
<CAPITAL-SURPLUS-PAID-IN>                                            534,588
<RETAINED-EARNINGS>                                                  265,912
<TOTAL-COMMON-STOCKHOLDERS-EQ>                                     1,562,636
<PREFERRED-MANDATORY>                                                      0
<PREFERRED>                                                           20,975
<LONG-TERM-DEBT-NET>                                               1,222,606
<SHORT-TERM-NOTES>                                                   301,989
<LONG-TERM-NOTES-PAYABLE>                                                  0
<COMMERCIAL-PAPER-OBLIGATIONS>                                             0
<LONG-TERM-DEBT-CURRENT-PORT>                                        130,000
<PREFERRED-STOCK-CURRENT>                                                  0
<CAPITAL-LEASE-OBLIGATIONS>                                                0
<LEASES-CURRENT>                                                           0
<OTHER-ITEMS-CAPITAL-AND-LIAB>                                     1,602,253
<TOT-CAPITALIZATION-AND-LIAB>                                      4,840,459
<GROSS-OPERATING-REVENUE>                                          1,100,627
<INCOME-TAX-EXPENSE>                                                  70,837
<OTHER-OPERATING-EXPENSES>                                           865,953
<TOTAL-OPERATING-EXPENSES>                                           936,790
<OPERATING-INCOME-LOSS>                                              163,837
<OTHER-INCOME-NET>                                                     1,910
<INCOME-BEFORE-INTEREST-EXPEN>                                       165,747
<TOTAL-INTEREST-EXPENSE>                                              59,994
<NET-INCOME>                                                         105,753
<PREFERRED-STOCK-DIVIDENDS>                                              436
<EARNINGS-AVAILABLE-FOR-COMM>                                        105,317
<COMMON-STOCK-DIVIDENDS>                                              85,200
<TOTAL-INTEREST-ON-BONDS>                                             57,876
<CASH-FLOW-OPERATIONS>                                               236,225
<EPS-PRIMARY>                                                           0.00
<EPS-DILUTED>                                                           0.00