Exhibit 10.23.1

                                 AMENDMENT No. 1

                                       TO


AGREEMENT AND PLAN OF MERGER





            This  Amendment  No. 1, dated as of December  31,  1999,  amends the
Agreement  and Plan of  Merger as of  December  21,  1997 by and among  American
Electric  Power  Company,   Inc.,  a  New  York  corporation  ("AEP"),   Augusta
Acquisition Corporation, a Delaware corporation and a wholly owned subsidiary of
AEP ("Augusta"),  and Central and South West Corporation, a Delaware corporation
(the  "Company").  All Orders  necessary for the consummation of the Merger have
not been obtained.

            The Board of  Directors  of the  Company,  the Board of Directors of
AEP, and the Board of Directors of Augusta have  determined that the Termination
Date of December 31, 1999 provided in Paragraph  9.1(f) of the Merger  Agreement
should be extended upon the terms and conditions set forth herein.

            NOW THEREFORE,  in consideration of the foregoing and the respective
agreements  set forth in this  Amendment  No.  l, the  parties  hereto  agree as
follows:

             1.   Paragraph  9.1(f) of the Merger Agreement is hereby amended so
                  that, as amended, it shall read in its entirety as follows.

                        "(f.)  Termination  Date  By either  AEP or the Company,
                        by written notice to the other, if the Merger shall  not
                        have  been   consummated  on  or  before   June 30, 2000
                        (`Termination Date')."

             2.   The Merger shall be  consummated  pursuant to Article 2 of the
                  Merger Agreement provided that on or before the Effective Date
                  all closing conditions set forth in the Merger Agreement shall
                  be satisfied or, if permitted by the Merger Agreement,  waived
                  in a writing given  subsequent  to the date of this  Amendment
                  No. 1.






             3.   This  Amendment  No. 1 is not and  shall not be deemed to be a
                  waiver of any rights or a release of any obligations of any of
                  the parties to the Merger Agreement whether based upon events,
                  facts or conditions  occurring or existing before or after the
                  date hereof.

             4.   Capitalized   terms  shall  have  the  same  meaning  in  this
                  Amendment No. 1 as in the Merger Agreement.

            IN WITNESS  WHEREOF,  each of the  parties  hereto  has caused  this
Amendment  No.  1 to be  executed  as of the  date  first  written  above by the
respective duly authorized officers thereunto duly authorized.

AMERICAN ELECTRIC POWER COMPANY, INC.




By:/s/ E.L. Draper, Jr.
   Name:  E.L. Draper, Jr.
   Title:



AUGUSTA ACQUISITION CORPORATION




By:/s/ E.L. Draper, Jr.
   Name:  E.L. Draper, Jr.
   Title




CENTRAL AND SOUTH WEST CORPORATION




By:/s/ E.R. Brooks
   Name:  E.R. Brooks
   Title: