
                                 Exhibit 10.12a

                             FIRST AMENDMENT TO THE
                        PINNACLE WEST CAPITAL CORPORATION
                          1994 LONG-TERM INCENTIVE PLAN

     Effective March 23, 1994, Pinnacle West Capital Corporation (the "Company")
established the Pinnacle West Capital  Corporation 1994 Long-Term Incentive Plan
(the  "Plan").  By this  instrument,  the  Company  intends to amend the Plan to
clarify  the  interaction  of the Plan  with the Key  Executive  Employment  and
Severance Agreements  ("KEESAs") entered into between the Company and certain of
its affiliates and their respective employees.

     1. This  Amendment  shall amend only those  sections  specified  herein and
those sections not amended hereby shall remain in full force and effect:

     2. The following new definitions are hereby added at the end of Section 2:

          w.  "Change of Control"  shall have the same  meaning as given to that
     term in the Participant's KEESA.

          x. "KEESA" means the Key Executive  Employment and Severance Agreement
     between the Company or a Subsidiary and a  Participant,  as the same may be
     amended from time to time.

          y. "Termination  Payment" shall have the same meaning as given to that
     term in the Participant's KEESA.

     3. A new  subsection g is hereby added to Section 7 of the Plan which shall
read as follows:

          g IMPACT OF A CHANGE OF CONTROL.  Notwithstanding any provision in the
     Plan or an Award  Agreement,  in the event  that a  Participant  terminates
     employment  following a Change of Control and thereby becomes entitled to a
     Termination  Payment under his or her KEESA,  any Options then  outstanding
     will become fully vested and  exercisable  in accordance  with the terms of
     the Plan.
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     4. The second paragraph of Section 9 is hereby amended to add the following
sentence:


     Notwithstanding  any  provision  in the Plan or an Award  Agreement  to the
     contrary, upon a Participant's termination of employment following a Change
     of Control which entitles such  Participant to a Termination  Payment under
     the  terms  of  his  or  her  KEESA,  any  restrictions  remaining  on  any
     outstanding Restricted Stock Award shall immediately lapse.

     5. Section 12 is hereby amended in its entirety to read as follows:

          12. CHANGES IN CAPITAL STRUCTURE

          In the event a stock  dividend is declared upon the Stock,  the shares
     of Stock then  subject  to each  Award  (and the  number of shares  subject
     thereto)  will be  increased  proportionately  without  any  change  in the
     aggregate purchase price therefor.  Subject to the provisions of Section 7g
     and 9, in the event the  Stock  will be  changed  into or  exchanged  for a
     different  number  of  class  of  shares  of  Stock  or  stock  of  another
     corporation,  whether  through  reorganization,   recapitalization,   stock
     split-up,  combination of shares,  merger or  consolidation,  there will be
     substituted  for each such share of Stock  then  subject to each Award (and
     for each  share of Stock  then  subject  thereto)  the  number and class of
     shares of Stock  into  which  each  outstanding  share of Stock  will be so
     exchanged,  all without any change in the aggregate  purchase price for the
     shares then subject to each Award.

          Subject to any  required  action by the  shareholders,  if the Company
     will  be  the  surviving  or  resulting   corporation   in  any  merger  or
     consolidation, any Award granted hereunder will pertain to and apply to the
     securities  or rights  to which a holder  of the  number of shares of Stock
     subject  to the Award  would  have been  entitled.  Upon a  dissolution  or
     liquidation  of the  Company  or a merger  or  consolidation  in which  the
     Company  is  not  the  surviving  or  resulting  corporation,  and  if  the
     provisions  of Section  7g and/or  Section 9 do not  apply,  the  Committee
     shall, in its discretion:

               (a) cause every Award outstanding hereunder to terminate,  except
          that the  surviving  or  resulting  corporation,  in its  absolute and
          uncontrolled  discretion,  may tender an option or options to purchase
          its shares or exercise such rights on terms and conditions,  as to the
          number of shares and rights and  otherwise,  which will  substantially
          preserve  the  rights  and  benefits  of any  Award  then  outstanding
          hereunder; or

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               (b) give each  Participant  the right to exercise Awards prior to
          the occurrence of the event otherwise terminating the Awards over such
          period as the  Committee,  in its sole and absolute  discretion,  will
          determine.  To the extent that this provision  causes a Participant to
          exceed the  requirements  of Section  7e, any excess  Incentive  Stock
          Options will be deemed to be noncapitalized-Qualified Stock Options.

     6. The provisions of this Amendment shall be effective as of July 1, 1999.

     Except as amended  hereby,  the Company  hereby  ratifies  and confirms the
terms of the Plan as adopted effective March 23, 1994.

     IN WITNESS WHEREOF, the Company has caused this Amendment to be executed on
its behalf by a duly authorized officer this 7 day of December, 1999.

                                        PINNACE WEST CAPITAL CORPORATION


                                        By Armando Flores
                                          --------------------------------------
                                        Its Executive VP CBS
                                           -------------------------------------

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