<TABLE> <S> <C>
<ARTICLE> UT
<CIK>0000081027
<NAME> PUBLIC SERVICE COMPANY OF OKLAHOMA
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 9-MOS
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-END> SEP-30-2000
<BOOK-VALUE> PER-BOOK
<TOTAL-NET-UTILITY-PLANT> 1,413,370
<OTHER-PROPERTY-AND-INVEST> 78,190
<TOTAL-CURRENT-ASSETS> 279,999
<TOTAL-DEFERRED-CHARGES> 11,777
<OTHER-ASSETS> 27,786
<TOTAL-ASSETS> 1,811,122
<COMMON> 157,230
<CAPITAL-SURPLUS-PAID-IN> 180,000
<RETAINED-EARNINGS> 158,272
<TOTAL-COMMON-STOCKHOLDERS-EQ> 495,502
0
5,283
<LONG-TERM-DEBT-NET> 419,745
<SHORT-TERM-NOTES> 119,689
<LONG-TERM-NOTES-PAYABLE> 0
<COMMERCIAL-PAPER-OBLIGATIONS> 0
<LONG-TERM-DEBT-CURRENT-PORT> 30,000
0
<CAPITAL-LEASE-OBLIGATIONS> 0
<LEASES-CURRENT> 0
<OTHER-ITEMS-CAPITAL-AND-LIAB> 740,903
<TOT-CAPITALIZATION-AND-LIAB> 1,811,122
<GROSS-OPERATING-REVENUE> 729,211
<INCOME-TAX-EXPENSE> 41,118
<OTHER-OPERATING-EXPENSES> 596,294
<TOTAL-OPERATING-EXPENSES> 637,412
<OPERATING-INCOME-LOSS> 91,799
<OTHER-INCOME-NET> 7,927
<INCOME-BEFORE-INTEREST-EXPEN> 99,726
<TOTAL-INTEREST-EXPENSE> 29,532
<NET-INCOME> 70,194
158
<EARNINGS-AVAILABLE-FOR-COMM> 70,036
<COMMON-STOCK-DIVIDENDS> 51,000
<TOTAL-INTEREST-ON-BONDS> 17,755
<CASH-FLOW-OPERATIONS> 143,214
<EPS-BASIC> 0.00<F1>
<EPS-DILUTED> 0.00<F1>
<FN>
<F1> ALL COMMON STOCK OWNED BY THE PARENT COMPANY; NO EPS REQUIRED
</FN>
</TABLE>
