<TABLE> <S> <C>

<ARTICLE> UT
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED
FROM (CONSOLIDATED INTERIM FINANCIAL STATEMENTS AS OF JUNE 30,
1998) AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                                                       <C>
<PERIOD-TYPE>                                                   6-MOS
<FISCAL-YEAR-END>                                         DEC-31-1997
<PERIOD-END>                                              JUN-30-1998
<BOOK-VALUE>                                                 PER-BOOK
<TOTAL-NET-UTILITY-PLANT>                                  $6,268,239
<OTHER-PROPERTY-AND-INVEST>                                  $253,380
<TOTAL-CURRENT-ASSETS>                                       $854,427
<TOTAL-DEFERRED-CHARGES>                                     $426,852
<OTHER-ASSETS>                                               $580,247
<TOTAL-ASSETS>                                             $8,383,145
<COMMON>                                                   $1,212,330
<CAPITAL-SURPLUS-PAID-IN>                                       ($790)
<RETAINED-EARNINGS>                                        $1,624,745
<TOTAL-COMMON-STOCKHOLDERS-EQ>                             $2,836,285
<PREFERRED-MANDATORY>                                              $0
<PREFERRED>                                                   $59,376
<LONG-TERM-DEBT-NET>                                       $2,581,325
<SHORT-TERM-NOTES>                                                 $0
<LONG-TERM-NOTES-PAYABLE>                                          $0
<COMMERCIAL-PAPER-OBLIGATIONS>                                     $0
<LONG-TERM-DEBT-CURRENT-PORT>                                $168,075
<PREFERRED-STOCK-CURRENT>                                          $0
<CAPITAL-LEASE-OBLIGATIONS>                                        $0
<LEASES-CURRENT>                                                   $0
<OTHER-ITEMS-CAPITAL-AND-LIAB>                             $2,738,084
<TOT-CAPITALIZATION-AND-LIAB>                              $8,383,145
<GROSS-OPERATING-REVENUE>                                  $1,488,447
<INCOME-TAX-EXPENSE>                                         $127,832
<OTHER-OPERATING-EXPENSES>                                 $1,109,025
<TOTAL-OPERATING-EXPENSES>                                 $1,236,857
<OPERATING-INCOME-LOSS>                                      $251,590
<OTHER-INCOME-NET>                                           ($10,299)
<INCOME-BEFORE-INTEREST-EXPEN>                               $241,291
<TOTAL-INTEREST-EXPENSE>                                      $89,252
<NET-INCOME>                                                 $152,039
<PREFERRED-STOCK-DIVIDENDS>                                   ($1,483)
<EARNINGS-AVAILABLE-FOR-COMM>                                $150,556
<COMMON-STOCK-DIVIDENDS>                                     $139,692
<TOTAL-INTEREST-ON-BONDS>                                     $67,166
<CASH-FLOW-OPERATIONS>                                       $347,557
<EPS-PRIMARY>                                                    1.05
<EPS-DILUTED>                                                    1.05
        

</TABLE>