EXHIBIT 24.21
                                   CERTIFICATE

      I, Martha  Murray,  Secretary  of West Texas  Utilities  Company,  a Texas
corporation  (the  "Corporation"),  hereby  certify  that set  forth  below is a
complete  and  accurate  copy of a certain  resolution  adopted  by the Board of
Directors of the  Corporation  on this 25th day of January,  2000, and that such
resolution is in full force and effect as of the date of this certificate.


                          West Texas Utilities Company
                          Board of Directors Resolution
                                January 25, 2000

      RESOLVED,  that each officer of West Texas Utilities Company listed at the
end of this sentence is hereby  authorized to make,  constitute and appoint,  in
his respective  capacity,  a power of attorney in favor of the person(s)  listed
directly  after  his name at the end of this  sentence,  as his true and  lawful
attorney(s)-in-fact and agent(s), with full power and authority (and in the case
of more  than one  attorney-in-fact,  each  attorney-in-fact  acting  alone  and
without the other) to execute in the name and on behalf of the  officer,  in any
and all capacities,  the  Corporation's  Annual Report on Form 10-K for 1999 and
any and all amendments thereto, to be filed under the Securities Exchange Act of
1934, as amended,  and any other documents and instruments  incidental  thereto,
and to file the same, with all exhibits  thereto and all documents in connection
therewith,  with the  Securities  and  Exchange  Commission,  and  grant to such
attorney(s)-in-fact,   and   agent(s)   (and  in  the  case  of  more  than  one
attorney-in-fact,  each of them),  full power and authority of substitution  and
revocation  in the premises and full power and  authority to do and perform each
and every  act and thing  requisite  and  necessary  to be done in and about the
premises, as fully and all intents and purposes as the officer might or could do
in person.

1.    Paul J. Brower is authorized to make,  constitute and appoint R. Russell
      Davis to be his attorney(s)-in-fact.
2.    R. Russell Davis is authorized to make,  constitute  and appoint Paul J.
      Brower to be his attorney(s)-in-fact.

      IN WITNESS  WHEREOF,  I have  hereunto set my hand and affixed the seal of
West Texas Utilities Company this day, the 25th of January, 2000.



      /s/ Martha Murray
           Martha Murray




      CORPORATE SEAL