<ARTICLE>  UT
<SUBSIDIARY>
<NUMBER> 004
<NAME>  PUBLIC SERVICE COMPANY OF OKLAHOMA
<MULTIPLIER> 1,000
       
                                         
<PERIOD-TYPE>                               6-MOS
<FISCAL-YEAR-END>                                      DEC-31-1998
<PERIOD-END>                                           JUN-30-1998
<BOOK-VALUE>                                              PER-BOOK
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<OTHER-ASSETS>                                              33,554
<TOTAL-ASSETS>                                           1,462,146
<COMMON>                                                   157,230
<CAPITAL-SURPLUS-PAID-IN>                                  180,000
<RETAINED-EARNINGS>                                        142,107
<TOTAL-COMMON-STOCKHOLDERS-EQ>                             479,337
<PREFERRED-MANDATORY>                                            0
<PREFERRED>                                                  5,287
<LONG-TERM-DEBT-NET>                                       402,582
<SHORT-TERM-NOTES>                                           3,740
<LONG-TERM-NOTES-PAYABLE>                                   40,000
<COMMERCIAL-PAPER-OBLIGATIONS>                                   0
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<LEASES-CURRENT>                                                 0
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<INCOME-TAX-EXPENSE>                                        12,282
<OTHER-OPERATING-EXPENSES>                                 288,121
<TOTAL-OPERATING-EXPENSES>                                 300,403
<OPERATING-INCOME-LOSS>                                     42,874
<OTHER-INCOME-NET>                                             382
<INCOME-BEFORE-INTEREST-EXPEN>                              43,256
<TOTAL-INTEREST-EXPENSE>                                    20,039
<NET-INCOME>                                                23,217
<PREFERRED-STOCK-DIVIDENDS>                                    106
<EARNINGS-AVAILABLE-FOR-COMM>                               23,111
<COMMON-STOCK-DIVIDENDS>                                    18,000
<TOTAL-INTEREST-ON-BONDS>                                   14,022
<CASH-FLOW-OPERATIONS>                                      54,104
<EPS-PRIMARY>                                                 0.00
<EPS-DILUTED>                                                 0.00