Exhibit 99.1
AEP, CSW Extend Merger Agreement

(Note: This is a press release issued jointly by AEP and CSW on Dec. 16.)

                         AEP, CSW AMEND MERGER AGREEMENT
                   TO EXTEND TERM FOR AN ADDITIONAL SIX MONTHS

Columbus, Ohio, and Dallas, Texas (Dec. 16, 1999) -- American Electric Power and
Central and South West Corp. have mutually agreed to amend the agreement for the
pending  merger of the two  companies  to  extend  its  term.  This  will  allow
additional  time to satisfy the closing  conditions  contained in the agreement.
This amendment to the merger  agreement,  approved by the boards of directors of
each  company,  requires that AEP and CSW gain final  approvals  before June 30,
2000. The original merger agreement listed a Dec. 31, 1999 deadline.

The merger has already received  approval from state  regulatory  commissions in
Arkansas,  Louisiana,  Oklahoma and Texas,  the four states within CSW's service
territory. In addition, the Nuclear Regulatory Commission has approved a license
transfer application for the transfer of control of CSW subsidiary Central Power
and Light's South Texas Nuclear Plant.

The merger  requires  additional  approvals  by the  Federal  Energy  Regulatory
Commission (FERC), the Securities and Exchange Commission (SEC) and clearance by
the Department of Justice under the Hart-Scott-Rodino Antitrust Improvements Act
of 1976. The  administrative law judge who presided over the FERC merger hearing
filed an initial  decision with the commission on Nov. 23 that found the AEP-CSW
merger  to be in the  public  interest.  The FERC  indicated  it will act on the
merger no later than  February  or March  2000.  The SEC review  will follow the
FERC's action.

Central and South West Corp. is a global,  diversified  public  utility  holding
company based in Dallas. CSW owns four electric operating  subsidiaries  serving
1.7 million  customers in Texas,  Oklahoma,  Louisiana and Arkansas;  a regional
electricity company in the United Kingdom; other international energy operations
and   non-utility   subsidiaries   involved   in   energy-related   investments,
telecommunications, energy efficiency and financial transactions.

AEP,  a  global  energy   company,   is  one  of  the  United  States'   largest
investor-owned  utilities,  providing energy to 3 million  customers in Indiana,
Kentucky,  Michigan,  Ohio,  Tennessee,  Virginia  and  West  Virginia.  AEP has
holdings in the United States, the United Kingdom,  China and Australia.  Wholly
owned  subsidiaries  provide power  engineering,  energy  consulting  and energy
management services around the world. The company is based in Columbus, Ohio.