<ARTICLE> UT
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-END>                               SEP-30-1997
<BOOK-VALUE>                                  PER-BOOK
<TOTAL-NET-UTILITY-PLANT>                    6,975,860
<OTHER-PROPERTY-AND-INVEST>                    235,341
<TOTAL-CURRENT-ASSETS>                         781,782
<TOTAL-DEFERRED-CHARGES>                        61,307
<OTHER-ASSETS>                                 991,552
<TOTAL-ASSETS>                               9,045,842
<COMMON>                                         1,372
<CAPITAL-SURPLUS-PAID-IN>                    1,582,938
<RETAINED-EARNINGS>                          1,523,429
<TOTAL-COMMON-STOCKHOLDERS-EQ>               3,107,739
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                    235,197
<LONG-TERM-DEBT-NET>                         2,407,940
<SHORT-TERM-NOTES>                               7,000
<LONG-TERM-NOTES-PAYABLE>                            0
<COMMERCIAL-PAPER-OBLIGATIONS>                  36,358
<LONG-TERM-DEBT-CURRENT-PORT>                   14,444
<PREFERRED-STOCK-CURRENT>                            0
<CAPITAL-LEASE-OBLIGATIONS>                     84,801
<LEASES-CURRENT>                                28,749
<OTHER-ITEMS-CAPITAL-AND-LIAB>               3,123,614
<TOT-CAPITALIZATION-AND-LIAB>                9,045,842
<GROSS-OPERATING-REVENUE>                    2,599,362
<INCOME-TAX-EXPENSE>                           227,735
<OTHER-OPERATING-EXPENSES>                   1,874,581
<TOTAL-OPERATING-EXPENSES>                   2,102,316
<OPERATING-INCOME-LOSS>                        497,046
<OTHER-INCOME-NET>                            (11,746)
<INCOME-BEFORE-INTEREST-EXPEN>                 485,300
<TOTAL-INTEREST-EXPENSE>                       135,819
<NET-INCOME>                                   340,086
<PREFERRED-STOCK-DIVIDENDS>                      9,395
<EARNINGS-AVAILABLE-FOR-COMM>                  340,086
<COMMON-STOCK-DIVIDENDS>                       261,395
<TOTAL-INTEREST-ON-BONDS>                            0
<CASH-FLOW-OPERATIONS>                         626,173
<EPS-PRIMARY>                                     2.48
<EPS-DILUTED>                                     2.48