<ARTICLE> UT <MULTIPLIER> 1,000 <PERIOD-TYPE> YEAR <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-END> SEP-30-1997 <BOOK-VALUE> PER-BOOK <TOTAL-NET-UTILITY-PLANT> 2,950,272 <OTHER-PROPERTY-AND-INVEST> 388,158 <TOTAL-CURRENT-ASSETS> 391,605 <TOTAL-DEFERRED-CHARGES> 94,180 <OTHER-ASSETS> 274,754 <TOTAL-ASSETS> 4,098,969 <COMMON> 291,458 <CAPITAL-SURPLUS-PAID-IN> 566,233 <RETAINED-EARNINGS> 499,158 <TOTAL-COMMON-STOCKHOLDERS-EQ> 1,356,849 <PREFERRED-MANDATORY> 25,000 <PREFERRED> 78,475 <LONG-TERM-DEBT-NET> 1,126,553 <SHORT-TERM-NOTES> 0 <LONG-TERM-NOTES-PAYABLE> 0 <COMMERCIAL-PAPER-OBLIGATIONS> 0 <LONG-TERM-DEBT-CURRENT-PORT> 52 <PREFERRED-STOCK-CURRENT> 0 <CAPITAL-LEASE-OBLIGATIONS> 91,598 <LEASES-CURRENT> 6,696 <OTHER-ITEMS-CAPITAL-AND-LIAB> 1,413,746 <TOT-CAPITALIZATION-AND-LIAB> 4,098,969 <GROSS-OPERATING-REVENUE> 1,552,825 <INCOME-TAX-EXPENSE> 161,102 <OTHER-OPERATING-EXPENSES> 1,164,577 <TOTAL-OPERATING-EXPENSES> 1,325,679 <OPERATING-INCOME-LOSS> 227,146 <OTHER-INCOME-NET> (297) <INCOME-BEFORE-INTEREST-EXPEN> 226,849 <TOTAL-INTEREST-EXPENSE> 65,098 <NET-INCOME> 161,751 <PREFERRED-STOCK-DIVIDENDS> 4,937 <EARNINGS-AVAILABLE-FOR-COMM> 156,814 <COMMON-STOCK-DIVIDENDS> 206,362 <TOTAL-INTEREST-ON-BONDS> 53,226 <CASH-FLOW-OPERATIONS> 432,873 <EPS-PRIMARY> 0 <EPS-DILUTED> 0