<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
       
                                                       
<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>                                          6,279,429
<OTHER-PROPERTY-AND-INVEST>                                                0
<TOTAL-CURRENT-ASSETS>                                               476,005
<TOTAL-DEFERRED-CHARGES>                                           1,123,400
<OTHER-ASSETS>                                                       884,496
<TOTAL-ASSETS>                                                     8,763,330
<COMMON>                                                               1,577
<CAPITAL-SURPLUS-PAID-IN>                                          1,570,533
<RETAINED-EARNINGS>                                                1,019,237
<TOTAL-COMMON-STOCKHOLDERS-EQ>                                     2,591,347
<PREFERRED-MANDATORY>                                                      0
<PREFERRED>                                                          194,048
<LONG-TERM-DEBT-NET>                                               2,133,475
<SHORT-TERM-NOTES>                                                 1,104,859
<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>                                     2,609,601
<TOT-CAPITALIZATION-AND-LIAB>                                      8,763,330
<GROSS-OPERATING-REVENUE>                                          1,895,513
<INCOME-TAX-EXPENSE>                                                 103,856
<OTHER-OPERATING-EXPENSES>                                         1,533,915
<TOTAL-OPERATING-EXPENSES>                                         1,637,771
<OPERATING-INCOME-LOSS>                                              257,742
<OTHER-INCOME-NET>                                                    36,792
<INCOME-BEFORE-INTEREST-EXPEN>                                       294,534
<TOTAL-INTEREST-EXPENSE>                                             118,453
<NET-INCOME>                                                         176,081
<PREFERRED-STOCK-DIVIDENDS>                                            6,475
<EARNINGS-AVAILABLE-FOR-COMM>                                        169,606
<COMMON-STOCK-DIVIDENDS>                                             141,910
<TOTAL-INTEREST-ON-BONDS>                                             94,252
<CASH-FLOW-OPERATIONS>                                               316,886
<EPS-PRIMARY>                                                           1.07
<EPS-DILUTED>                                                           1.07