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                                                                  Exhibit 10.64b

                              FOURTH AMENDMENT TO
                     THE PINNACLE WEST CAPITAL CORPORATION
                         ARIZONA PUBLIC SERVICE COMPANY
                           SUNCOR DEVELOPMENT COMPANY
                        AND EL DORADO INVESTMENT COMPANY
                           DEFERRED COMPENSATION PLAN


     Effective January 1, 1992, Pinnacle West Capital Corporation (the
"Company"), Arizona Public Service Company, SunCor Development Company and El
Dorado Investment Company adopted the Pinnacle West Capital Corporation,
Arizona Public Service Company, SunCor Development Company and El Dorado
Investment Company Deferred Compensation Plan (the "Plan"). The Plan was
thereafter amended several times. The Plan was amended and restated in its
entirety on December 1, 1995 and amended several times thereafter. The Plan was
most recently amended on October 22, 2002 to increase the threshold for
automatic cashout for terminated or retired Participants under certain
circumstances and revise crediting of interest for certain Participants.

     By this instrument, the Plan is being amended to revise its claims
procedures.

     1.   This Amendment shall amend only those Sections set forth herein and
those Sections not amended hereby shall remain in full force and effect.

     2.   Section 1.17 is hereby amended in its entirety to read as follows:

          1.17  "Disability" shall mean (i) in the case of a Participant who is
   an employee of an Employer, a period of disability during which a participant
   qualifies for benefits under the Participant's Employer's long-term
   disability plan, or (ii) in the case of a Participant who is a Director, a
   period of disability during
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     which the Participant would have qualified for benefits under such a plan,
     as determined in the sole discretion of the Committee, had the Participant
     been an employee of an Employer.

     3.   Section 8.1(b) is hereby amended in its entirety to read as follows:

          (b)  Waiver of Deferral; Credit for Plan Year of Disability. A
               Participant who is determined to be suffering from a Disability
               shall be excused from fulfilling that portion of the Annual
               Deferral commitment that would otherwise have been withheld from
               a Participant's Base Annual Salary, Year-End Bonus and/or
               Directors Fees for the Plan Year during which the Participant
               first suffers a Disability. In addition, the Participant's
               Account Balance shall be credited with that portion of the Annual
               Deferral commitment that is excused in accordance with the
               preceding sentence, unless the Disability ceases in the Plan Year
               that it commences, in which case, the crediting shall apply only
               for the period of Disability.

     4.   Section 8.2 is hereby amended in its entirety to read as follows:

     8.2  Disability Benefit. A Participant suffering a Disability shall, for
          benefit purposes under this Plan, continue to be considered to be
          employed and shall be eligible for the benefits provided for in
          Articles 4, 5, 6 or 7 in accordance with the provisions of those
          Articles. Notwithstanding the above, the Committee shall have the
          right, in its sole and absolute discretion and for purposes of this
          Plan only, to terminate a Participant's employment or service as a
          Director at any time after such Participant is determined to be
          suffering from a Disability. In determining the Participant's Account
          Balance for purposes of the Disability Benefit described in the
          previous sentence, the Preferred Rate shall be used in lieu of the
          rates specified in Section 7.1.



     5.   ARTICLE 14 is hereby amended in its entirety to read as follows:

                                   ARTICLE 14

                               Claims Procedures

          14.1 Claims. Any Participant, Beneficiary or any authorized
     representative acting on behalf of the Participant or Beneficiary
     ("Claimant")



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claiming benefits, eligibility, participation or any other right or interest
under this Plan may file a written claim setting forth the basis of the claim
with the Employee Benefits Department. A written notice of the Employee Benefits
Department's disposition of any such claim shall be furnished to the Claimant
within a reasonable time (not to exceed ninety (90) days) after the claim is
received by the Employee Benefits Department. Notwithstanding the foregoing, the
Employee Benefits Department may have additional time (not to exceed ninety (90)
days) to decide the claim if special circumstances exist, provided that it
advises the Claimant, in writing and prior to the end of the initial ninety (90)
day period, of the special circumstances giving rise to the need for additional
time and the date on which it expects to decide the claim. If the claim is
denied, in whole or in part, the notice of disposition shall include the
specific reason for the denial, identify the specific provisions of the Plan
upon which the denial is based, describe any additional material or information
necessary to perfect the claim, explain why that material or information is
necessary and describe the Plan's review procedures, including the timeframes
thereunder for a Claimant to file a request for review and for the Committee to
decide the claim. The notice shall also include a statement advising the
claimant of his or her right to bring a civil action under Section 502(a) of the
Employee Retirement Income Security Act of 1974, as amended, if his or her claim
is denied, in whole or in part, upon review.

     Within sixty (60) days after receiving the written notice of the Employee
Benefits Department's disposition of the claim, the Claimant may request, in
writing, review by the Committee of the Employee Benefits Department's decision
regarding his or her claim. Upon written request, the Claimant shall be
entitled to a review meeting with the Committee to present reasons why the
claim should be allowed. The Claimant may submit a written statement in support
of his or her claim, together with such comments, information and material
relating to the claim, as he or she deems necessary or appropriate. The
Claimant shall be provided, upon request and free of charge, reasonable access
to, and copies of, all documents, records and other information which are
relevant to the Claimant's claim and its review. If the Claimant does not
request review within sixty (60) days after receiving written notice of the
Employee Benefits Department's disposition of the claim, the Claimant shall be
deemed to have accepted the Employee Benefits Department's written disposition.

     The Committee shall make its decision on review and provide written notice
thereof to the Claimant within a reasonable time (not to exceed sixty (60)
days) after the claim is received by the Committee. Notwithstanding the
foregoing, the Committee may have additional time (not to exceed sixty (60)
days) to decide the claim if special circumstances exist provided that it
advises the Claimant, in writing, prior to the end of the initial sixty (60)
day period, of the special circumstances giving rise to the need for additional
time and the date on which it expects to decide the claim. In no event shall
the Committee have more than one hundred twenty (120) days following its
receipt of the Claimant's request for review to provide the Claimant with
written notice of its decision.

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     The Committee shall have the right to request of and receive from Claimant
such additional information, documents or other evidence as the Committee may
reasonably require. In the event that the Committee requests such additional
information from the Claimant, the period for making the benefit determination
on review shall not take into account the period beginning on the date on which
the Committee notifies the Claimant in writing of the need for additional
information and ending on the date on which the Claimant responds to the request
for additional information.

     If the claim is denied upon review, in whole or in part, the notice of
disposition shall include the specific reason for the denial, identify the
specific provision of the Plan upon which the denial is based, include a
statement advising the Claimant of his or her right to receive, upon written
request and free of charge, reasonable access to and copies of all documents,
records and other information which are relevant to the Claimant's claim. The
notice shall also include a statement advising the claimant of his or her right
to bring a civil action under Section 502(a) of the Employee Retirement Income
Security Act of 1974, as amended, if his or her claim is denied, in whole or in
part, upon review.

     For purposes of this Section 14.1, a document, record or information will
be considered "relevant" if it (a) was relied upon by the Employee Benefits
Department or Committee, as applicable, in making the benefit decision, (b) was
submitted, considered or generated in the course of making such decisions, even
if it was not relied upon in making those decisions, or (c) demonstrates
compliance with the administrative processes and safeguards established by the
Plan to insure that the terms of the Plan have been followed and applied
consistently.

     To the extent permitted by law, a decision on review by the Committee shall
be binding and conclusive upon all persons whomsoever. Completion of the claims
procedure described in this Section 14.1 shall be a mandatory precondition that
must be complied with prior to commencement of a legal or equitable action in
connection with the Plan by a person claiming rights under the Plan, or by
another person claiming rights through such a person. The Committee may, in its
sole discretion, waive these procedures as a mandatory precondition to such an
action.


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     6.   Except as otherwise expressly provided herein, this Amendment shall
be effective January 1, 2003.

     Except as amended hereby, the Company ratifies and confirms the Plan as
amended and restated effective January 1, 1995, and as thereafter amended.

                              Date: December 18, 2003

                              PINNACLE WEST CAPITAL CORPORATION

                              By /s/ Jack Davis
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                                Its COO PNW/CEO APS & Pres
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