<ARTICLE> UT
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   12-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-END>                               DEC-31-1997
<BOOK-VALUE>                                  PER-BOOK
<TOTAL-NET-UTILITY-PLANT>                    2,854,127
<OTHER-PROPERTY-AND-INVEST>                    194,196
<TOTAL-CURRENT-ASSETS>                         318,525
<TOTAL-DEFERRED-CHARGES>                       255,499
<OTHER-ASSETS>                                       0
<TOTAL-ASSETS>                               3,622,347
<COMMON>                                        48,515
<CAPITAL-SURPLUS-PAID-IN>                      696,137
<RETAINED-EARNINGS>                            328,802
<TOTAL-COMMON-STOCKHOLDERS-EQ>               1,073,454
<PREFERRED-MANDATORY>                           78,093
<PREFERRED>                                     83,000
<LONG-TERM-DEBT-NET>                         1,057,076
<SHORT-TERM-NOTES>                              94,013
<LONG-TERM-NOTES-PAYABLE>                            0
<COMMERCIAL-PAPER-OBLIGATIONS>                  43,000
<LONG-TERM-DEBT-CURRENT-PORT>                  100,667
<PREFERRED-STOCK-CURRENT>                        2,000
<CAPITAL-LEASE-OBLIGATIONS>                          0
<LEASES-CURRENT>                                     0
<OTHER-ITEMS-CAPITAL-AND-LIAB>               1,091,044
<TOT-CAPITALIZATION-AND-LIAB>                3,622,347
<GROSS-OPERATING-REVENUE>                    1,776,233
<INCOME-TAX-EXPENSE>                            95,021
<OTHER-OPERATING-EXPENSES>                   1,420,362
<TOTAL-OPERATING-EXPENSES>                   1,515,383
<OPERATING-INCOME-LOSS>                        260,850
<OTHER-INCOME-NET>                            (10,498)
<INCOME-BEFORE-INTEREST-EXPEN>                 250,352
<TOTAL-INTEREST-EXPENSE>                       105,710
<NET-INCOME>                                   144,642
<PREFERRED-STOCK-DIVIDENDS>                     13,149
<EARNINGS-AVAILABLE-FOR-COMM>                  131,493
<COMMON-STOCK-DIVIDENDS>                        91,208
<TOTAL-INTEREST-ON-BONDS>                        3,280
<CASH-FLOW-OPERATIONS>                         359,230
<EPS-PRIMARY>                                     2.71
<EPS-DILUTED>                                     2.71