<ARTICLE> UT
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1997
<PERIOD-END>                               JUN-30-1997
<BOOK-VALUE>                                  PER-BOOK
<TOTAL-NET-UTILITY-PLANT>                    2,655,863
<OTHER-PROPERTY-AND-INVEST>                    788,437
<TOTAL-CURRENT-ASSETS>                         554,850
<TOTAL-DEFERRED-CHARGES>                       657,203
<OTHER-ASSETS>                                       0
<TOTAL-ASSETS>                               4,656,353
<COMMON>                                        73,119
<CAPITAL-SURPLUS-PAID-IN>                      916,628
<RETAINED-EARNINGS>                            816,890
<TOTAL-COMMON-STOCKHOLDERS-EQ>               1,432,892<F1>
<PREFERRED-MANDATORY>                            3,000
<PREFERRED>                                    221,238<F2>
<LONG-TERM-DEBT-NET>                         1,356,364
<SHORT-TERM-NOTES>                                   0
<LONG-TERM-NOTES-PAYABLE>                       38,000
<COMMERCIAL-PAPER-OBLIGATIONS>                       0
<LONG-TERM-DEBT-CURRENT-PORT>                  121,918
<PREFERRED-STOCK-CURRENT>                            0
<CAPITAL-LEASE-OBLIGATIONS>                     22,768
<LEASES-CURRENT>                                18,334
<OTHER-ITEMS-CAPITAL-AND-LIAB>               1,441,839
<TOT-CAPITALIZATION-AND-LIAB>                4,656,353
<GROSS-OPERATING-REVENUE>                      587,584
<INCOME-TAX-EXPENSE>                            43,816<F3>
<OTHER-OPERATING-EXPENSES>                     455,136
<TOTAL-OPERATING-EXPENSES>                     455,136
<OPERATING-INCOME-LOSS>                        132,448
<OTHER-INCOME-NET>                              60,952
<INCOME-BEFORE-INTEREST-EXPEN>                 193,400
<TOTAL-INTEREST-EXPENSE>                        57,709<F4>
<NET-INCOME>                                    91,875
<PREFERRED-STOCK-DIVIDENDS>                          0
<EARNINGS-AVAILABLE-FOR-COMM>                   91,875
<COMMON-STOCK-DIVIDENDS>                        52,592
<TOTAL-INTEREST-ON-BONDS>                       43,754
<CASH-FLOW-OPERATIONS>                         150,608
<EPS-PRIMARY>                                     1.19
<EPS-DILUTED>                                     1.19
<FN>
<F1>INCLUDES $(373,745) OF TREASURY STOCK AT COST
<F2>INCLUDES $10,630 OF PREFERENCE STOCK
<F3>NON-OPERATING EXPENSE
<F4>INCLUDES $8,434 OF PREFERRED AND PREFERENCE STOCK DIVIDENDS
</FN>