<ARTICLE> OPUR1

                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-END>                               JUN-30-1999
<BOOK-VALUE>                                  PER-BOOK
<TOTAL-NET-UTILITY-PLANT>                    4,723,441
<OTHER-PROPERTY-AND-INVEST>                    110,424
<TOTAL-CURRENT-ASSETS>                         292,471
<TOTAL-DEFERRED-CHARGES>                       502,185
<OTHER-ASSETS>                                  63,472
<TOTAL-ASSETS>                               5,691,993
<COMMON>                                       117,087
<CAPITAL-SURPLUS-PAID-IN>                      405,092
<RETAINED-EARNINGS>                            959,221
<TOTAL-COMMON-STOCKHOLDERS-EQ>               1,552,200
<PREFERRED-MANDATORY>                           76,532
<PREFERRED>                                     17,928
<LONG-TERM-DEBT-NET>                         2,380,678
<SHORT-TERM-NOTES>                             150,951
<LONG-TERM-NOTES-PAYABLE>                            0
<COMMERCIAL-PAPER-OBLIGATIONS>                       0
<LONG-TERM-DEBT-CURRENT-PORT>                   58,741
<PREFERRED-STOCK-CURRENT>                            0
<CAPITAL-LEASE-OBLIGATIONS>                          0
<LEASES-CURRENT>                                     0
<OTHER-ITEMS-CAPITAL-AND-LIAB>               1,454,963
<TOT-CAPITALIZATION-AND-LIAB>                5,691,993
<GROSS-OPERATING-REVENUE>                      596,391
<INCOME-TAX-EXPENSE>                            36,999
<OTHER-OPERATING-EXPENSES>                     410,165
<TOTAL-OPERATING-EXPENSES>                     447,164
<OPERATING-INCOME-LOSS>                        149,227
<OTHER-INCOME-NET>                             (7,371)
<INCOME-BEFORE-INTEREST-EXPEN>                 141,856
<TOTAL-INTEREST-EXPENSE>                        88,312
<NET-INCOME>                                    53,544
<PREFERRED-STOCK-DIVIDENDS>                      1,992
<EARNINGS-AVAILABLE-FOR-COMM>                   51,552
<COMMON-STOCK-DIVIDENDS>                        37,765
<TOTAL-INTEREST-ON-BONDS>                       78,968
<CASH-FLOW-OPERATIONS>                          98,500
<EPS-BASIC>                                      .54
<EPS-DILUTED>                                      .54