ARIZONA PUBLIC SERVICE COMPANY

                                   SECURITIES


                             UNDERWRITING AGREEMENT


                                                                November 2, 1999

Chase Securities Inc.
Credit Suisse First Boston Corporation
Salomon Smith Barney Inc.

Dear Sir or Madam:

     1.  INTRODUCTION.  Arizona Public Service Company,  an Arizona  corporation
(the "Company"), proposes to issue and sell from time to time up to $275,000,000
in  aggregate  principal  amount  of its  unsecured  debentures,  notes or other
evidences of indebtedness (the  "Securities")  registered under the registration
statement  referred to in Section 2(a). The Securities  will be issued under the
Indenture,  dated as of January  15,  1998,  between  the  Company and The Chase
Manhattan  Bank,  as  Trustee  (the  "Original   Indenture"),   as  amended  and
supplemented by one or more Supplemental  Indentures between the Company and the
Trustee (each, a "Supplemental  Indenture")  (the Original  Indenture as amended
and supplemented by such  Supplemental  Indentures  being sometimes  hereinafter
referred to as the  "Indenture").  The Securities  will be issued in one or more
series,  which  series may vary as to  interest  rates,  maturities,  redemption
provisions,  selling  prices,  and  other  terms,  with all such  terms  for any
particular  issue  of the  Securities  being  determined  at the  time of  sale.
Particular issues of the Securities may be sold from time to time to one or more
of the firms to whom this Agreement is addressed,  and to such other  purchasers
as the Company shall  designate and as shall agree in writing to comply with the
terms and conditions of this Agreement,  for resale in accordance with the terms
of offering  determined at the time of sale. The Securities involved in any such
offering are hereinafter referred to as the "Purchased Securities," the party or
parties  that agree to  purchase  the same are  hereinafter  referred  to as the
"Underwriters"  of  such  Purchased   Securities,   and  the  representative  or
representatives  of the  Underwriters,  if any,  specified in a Terms  Agreement
referred to in Section 3 are hereinafter referred to as the "Representatives."

     2.  REPRESENTATIONS  AND WARRANTIES OF THE COMPANY. In connection with each
offering of the Purchased  Securities,  the Company  represents and warrants to,
and agrees with, the Underwriters that:

          (a) A registration  statement (No. 333-58445) relating to $350,000,000
     of the Securities, the Company's first

     mortgage  bonds (the "Bonds"),  or the Company's  senior notes (the "Senior
     Notes") (including a combined  prospectus relating to up to $350,000,000 of
     the  Securities,  Bonds or Senior Notes) was filed with the  Securities and
     Exchange  Commission  (the  "Commission")  and has become  effective.  Such
     registration  statement,  as  amended  at the time of the  Terms  Agreement
     referred to in Section 3 relating  to the  Purchased  Securities,  together
     with any related 462(b)  registration  statement or amendment  thereto,  is
     hereinafter   referred  to  as  the   "Registration   Statement"  and  such
     prospectus,  as  supplemented  as  contemplated by Section 3 to reflect the
     terms of the Purchased Securities and terms of offering thereof,  including
     all material  incorporated by reference therein, is hereinafter referred to
     as the "Prospectus."

          (b)  Each  part  of  the  Registration   Statement   relating  to  the
     Securities,  when such part became  effective,  conformed  in all  material
     respects to the requirements of the Securities Act of 1933 (the "Act"), the
     Trust  Indenture Act of 1939 (the "Trust  Indenture Act") and the rules and
     regulations  (the "Rules and  Regulations")  of the  Commission and did not
     include  any  untrue  statement  of a  material  fact or omit to state  any
     material  fact  required  to be stated  therein  or  necessary  to make the
     statements  therein  not  misleading,  and on the  date of each  Prospectus
     Supplement  referred to in Section 3, the  Registration  Statement  and the
     Prospectus will conform in all material respects to the requirements of the
     Act, the Trust  Indenture  Act and the Rules and  Regulations,  and at such
     date none of such documents will include any untrue statement of a material
     fact or omit to state any material  fact  required to be stated  therein or
     necessary to make the statements therein not misleading; provided, however,
     that the foregoing  does not apply to (a)  statements in or omissions  from
     any such documents based upon written information  furnished to the Company
     by any  Underwriter  specifically  for use  therein or (b) that part of the
     Registration  Statement that consists of the Statement of  Eligibility  and
     Qualification (Form T-1) under the Trust Indenture Act of 1939 of The Chase
     Manhattan Bank, as Trustee under the Indenture.

          (c) An order of the Arizona  Corporation  Commission  has been granted
     authorizing  the  execution  and  delivery  of the  Supplemental  Indenture
     relating  to the  Purchased  Securities  and the  issuance  and sale of the
     Purchased  Securities  on  the  terms  and  conditions  herein  and  in the
     Prospectus and the Terms Agreement referred to in Section 3 relating to the
     Purchased  Securities,  and the approval or consent of no other public body
     or  authority  is  necessary  to  the   execution   and  delivery  of  such
     Supplemental  Indenture  or the  validity of the  issuance  and sale of the
     Purchased  Securities,  except as may be required under state securities or
     blue sky laws.

                                       2

          (d)  The  Company  holds  such  valid   franchises,   certificates  of
     convenience  and  necessity,  licenses,  and permits as are necessary  with
     respect to the  maintenance  and  operation of its property and business as
     now  conducted,  except that (A) the Company  from time to time makes minor
     extensions   of  its  system  prior  to  the  time  a  related   franchise,
     certificate,  license,  or  permit  is  procured,  (B)  from  time  to time
     communities  already being served by the Company  become  incorporated  and
     considerable  time may elapse  before a franchise is procured,  (C) certain
     franchises  may have expired prior to the  renegotiation  thereof,  (D) the
     Company may not have obtained certain permits or variances  relating to the
     environmental  requirements  described in any of its Form 10-K Report,  its
     Form 10-Q Reports, and/or its Form 8-K Reports incorporated by reference in
     the  Registration  Statement,  (E) certain minor defects and exceptions may
     exist which,  individually  and in the aggregate,  are not deemed material,
     and  (F) the  Company  does  not  make  any  representation  regarding  the
     geographical scope of any franchise,  certificate,  license, or permit that
     is not specific as to its geographical scope.

     3. PURCHASE AND OFFERING.  The obligation of the  Underwriters to purchase,
and the  obligation  of the Company to sell,  the Purchased  Securities  will be
evidenced  by  an  exchange  of   facsimile   transmission   or  other   written
communications  (the "Terms  Agreement")  at the time the Company  determines to
sell  the  Purchased   Securities.   The  Terms   Agreement  shall  specify  (by
incorporation  by  reference  or  otherwise)  the party or parties  that will be
Underwriters,  the principal  amount to be purchased by each, the purchase price
to be paid by the  Underwriters,  any  compensation or commissions to be paid to
Underwriters,  the offering price, and the terms of the Purchased Securities not
already  specified in the  Indenture,  including,  but not limited to,  interest
rates, maturity,  redemption provisions, and sinking fund requirements,  if any.
The Terms  Agreement  shall also  specify  (by  incorporation  by  reference  or
otherwise) the time and date of delivery and payment (the "Closing  Date"),  the
place of delivery  and  payment,  and any details of the terms of offering  that
should be reflected in the prospectus supplement relating to the offering of the
Purchased  Securities (the "Prospectus  Supplement").  It is understood that the
Underwriters  will offer the Purchased  Securities  for sale as set forth in the
Prospectus.  The  obligations  of the  Underwriters  to purchase  the  Purchased
Securities shall be several and not joint.  Except as may otherwise be set forth
in the Terms Agreement,  the Purchased Securities will be in definitive form and
in such  denominations  and  registered  in such names as the  Underwriters  may
request.

     4. COVENANTS OF THE COMPANY.  In connection with each offering of Purchased
Securities, the Company covenants and agrees with the several Underwriters that:

                                       3

          (a) The Company will advise the  Underwriters  or the  Representatives
     promptly of any proposed  amendment or  supplementation of the Registration
     Statement or the Prospectus.  The Company will also advise the Underwriters
     or the  Representatives  of the  institution  by the Commission of any stop
     order  proceedings in respect of the Registration  Statement or of any part
     thereof,  and will use its best efforts to prevent the issuance of any such
     stop order and to obtain as soon as possible its lifting, if issued.

          (b) If,  at any  time  when a  prospectus  relating  to the  Purchased
     Securities is required to be delivered under the Act, any event occurs as a
     result  of which the  Prospectus  as then  amended  or  supplemented  would
     include  an  untrue  statement  of a  material  fact,  or omit to state any
     material fact necessary to make the statements therein, in the light of the
     circumstances  under  which they were  made,  not  misleading,  or if it is
     necessary at any time to amend or supplement the Registration  Statement or
     the  Prospectus  to comply with the Act, the Company  promptly will prepare
     and file with the  Commission an amendment or supplement  that will correct
     such   statement  or  omission  or  an  amendment  that  will  effect  such
     compliance.

          (c) As soon as  practicable,  but not later than 18 months,  after the
     date of the Terms  Agreement  relating  to the  Purchased  Securities,  the
     Company will make  generally  available to its security  holders an earning
     statement or statements (which need not be audited) covering a period of at
     least 12 months  beginning  after the  effective  date of the  Registration
     Statement (as defined in Rule 158(c) under the Act), which will satisfy the
     provisions  of  Section  11(a)  of the Act and the  rules  and  regulations
     thereunder.

          (d)  The   Company   will   furnish   to  the   Underwriters   or  the
     Representatives  such copies of the Registration  Statement  (including one
     copy of the  Registration  Statement for each  Representative,  or for each
     Underwriter  if there are no  Representatives,  and for the counsel for the
     Underwriters,  which is signed and  includes  all  exhibits),  any  related
     preliminary  prospectus  supplements  and  the  Prospectus,  including  all
     amendments  or  supplements  to  such  documents,   as  may  be  reasonably
     requested.

          (e) The Company  will arrange or  cooperate  in  arrangements  for the
     qualification of the Purchased Securities for sale and the determination of
     their  eligibility for investment  under the laws of such  jurisdictions as
     the  Underwriters or the  Representatives  designate and will continue such
     qualifications  in effect so long as required for the  distribution  of the
     Purchased  Securities,  provided  that the Company shall not be required to
     qualify as a foreign  corporation  in any  State,  to consent to service of
     process in any State other than with respect to

                                       4

     claims arising out of the offering or sale of the Purchased Securities,  or
     to meet other requirements deemed by it to be unduly burdensome.

          (f)  During  the  period  of five  years  after  the date of the Terms
     Agreement relating to the Purchased Securities, the Company will furnish to
     the Underwriters or the Representatives thereunder, and, upon request, each
     of the other Underwriters, (i) as soon as practicable after the end of each
     fiscal year, a balance sheet and statements of income and retained earnings
     of the Company as at the end of and for such year, all in reasonable detail
     and certified by independent  public  accountants,  and (ii) (A) as soon as
     practicable  after the end of each quarterly  fiscal period (except for the
     last  quarterly  fiscal  period of each fiscal  year),  a balance sheet and
     statement  of income of the  Company as at the end of and for such  period,
     all  in  reasonable  detail  and  certified  by a  principal  financial  or
     accounting officer of the Company, (B) as soon as available, a copy of each
     report of the Company mailed by the Company to  stockholders  or filed with
     the  Commission,  and  (C)  from  time  to  time,  such  other  information
     concerning  the  Company as may  reasonably  be  requested.  So long as the
     Company has active  subsidiaries,  such financial  statements  will be on a
     consolidated  basis to the  extent  the  accounts  of the  Company  and its
     subsidiaries are consolidated.

          (g) The Company will pay all expenses  incident to the  performance of
     its obligations  under this Agreement,  and will reimburse the Underwriters
     for any reasonable expenses (including reasonable fees and disbursements of
     counsel)  incurred  by them in  connection  with the  qualification  of the
     Purchased  Securities with respect to which the Terms Agreement relating to
     the Purchased  Securities has been entered for sale, and the  determination
     of their eligibility for investment,  under the laws of such  jurisdictions
     as  the  Representatives   or,  if  there  are  no   Representatives,   the
     Underwriters designate, and the printing of memoranda relating thereto, and
     for any fees charged by  investment  rating  agencies for the rating of the
     Purchased Securities.

          (h) The Company will not offer or sell any other of its Securities for
     a period beginning at the time of execution of the Terms Agreement relating
     to the Purchased Securities and ending on the Closing Date relating thereto
     without prior consent of the Underwriter or the Representatives.

     5.  CONDITIONS OF THE OBLIGATIONS OF THE  UNDERWRITERS.  The obligations of
the  Underwriters  to  purchase  and pay for the  Purchased  Securities  will be
subject to the accuracy of the representations and warranties on the part of the
Company  herein,  to the accuracy of the  statements  of Company  officers  made
pursuant to the provisions hereof, to the performance by the

                                       5

Company of its obligations hereunder, and to the following additional conditions
precedent:

          (a) The  Underwriters  or the  Representatives  shall have  received a
     letter from DELOITTE & TOUCHE LLP,  dated the date of the Terms  Agreement,
     confirming that they are independent  certified public  accountants  within
     the meaning of the Act and the applicable  published  Rules and Regulations
     thereunder,  and stating in effect that (i) in their  opinion the financial
     statements and schedules of the Company audited by them and incorporated by
     reference in the  Registration  Statement comply as to form in all material
     respects with the  applicable  accounting  requirements  of the  Securities
     Exchange  Act of  1934  (the  "1934  Act")  and  the  published  Rules  and
     Regulations  thereunder  and (ii) on the basis of a reading  of the  latest
     available  interim  financial  statements  of  the  Company,  inquiries  of
     officials of the Company  responsible for financial and accounting matters,
     and other specified procedures, nothing came to their attention that caused
     them to believe that (A) the unaudited financial statements incorporated by
     reference,  if any, in the Registration  Statement do not comply as to form
     in all material respects with the applicable accounting requirements of the
     1934 Act and the  published  Rules and  Regulations  thereunder  or are not
     stated  on a  basis  substantially  consistent  with  that  of the  audited
     financial   statements   incorporated  by  reference  in  the  Registration
     Statement, (B) at the date of the most recent available unaudited financial
     statements  and at a  specified  date not more than five days  prior to the
     date of this  Agreement,  there was any  increase  in the amounts of common
     stock, redeemable preferred stock, or non-redeemable preferred stock of the
     Company or any increase,  exceeding  $10,000,000,  in long-term debt of the
     Company or, at the date of the most recent  available  unaudited  financial
     statements  there was any  decrease in net assets as compared  with amounts
     shown in the most recent financial statements  incorporated by reference in
     the Registration Statement, or (C) for the twelve-month period ended at the
     date of the most recent available unaudited financial statements there were
     any decreases, exceeding 3%, as compared with the twelve-month period ended
     at the  date  of the  most  recent  financial  statements  incorporated  by
     reference in the Registration  Statement,  in the amounts of total revenues
     or net income,  except in all cases for increases or decreases which result
     from the  declaration  or payment of dividends,  or which the  Registration
     Statement  (including  any  material  incorporated  by  reference  therein)
     disclose have occurred or may occur, or which are described in such letter.

          (b) No stop order  suspending the  effectiveness  of the  Registration
     Statement or any part thereof shall have been issued and no proceedings for
     that purpose shall have been instituted or, to the knowledge of the Company
     or the Underwriters, shall be contemplated by the Commission.

                                       6

          (c) Subsequent to the execution of the Terms Agreement relating to the
     Purchased Securities,  (i) there shall not have occurred any change, or any
     development  involving a prospective  change, in or affecting  particularly
     the business or properties of the Company or its subsidiaries which, in the
     judgment of a majority in  interest  of the  Underwriters  under such Terms
     Agreement, including any Representatives, materially impairs the investment
     quality of the Purchased  Securities,  (ii) there shall not have occurred a
     suspension or material limitation in trading in securities generally on the
     New York Stock  Exchange,  (iii)  there  shall not have  occurred a general
     moratorium on commercial  banking activities in New York declared by either
     Federal  or New  York  State  authorities,  (iv)  no  rating  of any of the
     Company's debt securities shall have been lowered and there shall have been
     no public  announcement  that any such debt  securities have been placed on
     CreditWatch,  Watchlist,  or under any similar  surveillance or review,  in
     each case with negative implications,  by any recognized rating agency, and
     (v) there  shall not have  occurred  any  outbreak or  escalation  of major
     hostilities in which the United States is involved,  any declaration of war
     by Congress or any other substantial national or international  calamity or
     emergency if, in the judgment of a majority in interest of the Underwriters
     under such Terms Agreement,  including any  Representatives,  the effect of
     any such outbreak, escalation,  declaration, calamity or emergency makes it
     impractical or  inadvisable  to proceed with  completion of the sale of and
     payment for the Purchased Securities.

          (d) The  Underwriters  or the  Representatives  shall have received an
     opinion  of Snell & Wilmer  L.L.P.,  counsel  for the  Company,  dated  the
     relevant Closing Date, to the effect that:

               (i)  The  Company  is  a  corporation  duly  organized,   validly
          existing,  and in good standing under the laws of the State of Arizona
          and has full corporate power and authority to carry on its business as
          presently  conducted;  and the Company is duly  qualified as a foreign
          corporation  to do business  and is in good  standing in the States of
          New  Mexico,  California,  Oregon,  Washington,  Montana,  Wyoming and
          Texas,  the  only  other  jurisdictions  in  which  it owns or  leases
          substantial  properties  or in  which  the  conduct  of  its  business
          requires such qualification;

               (ii)  The  Purchased   Securities  have  been  duly   authorized,
          executed,  authenticated,  issued, and delivered, and constitute valid
          and  legally  binding   obligations  of  the  Company  enforceable  in
          accordance  with  their  terms,  subject  to  bankruptcy,  insolvency,
          fraudulent transfer,

                                       7

          reorganization,  moratorium, and similar laws of general applicability
          relating  to or  affecting  creditors'  rights and to  general  equity
          principles and conform to the description thereof in the Prospectus;

               (iii) The  Indenture  has been  duly  authorized,  executed,  and
          delivered,  has been duly qualified under the Trust Indenture Act, and
          constitutes  a valid and  legally  binding  obligation  of the Company
          enforceable  in  accordance  with its terms,  subject  to  bankruptcy,
          insolvency,  fraudulent  transfer,  reorganization,   moratorium,  and
          similar  laws  of  general  applicability  relating  to  or  affecting
          creditors' rights and to general equity principles;

               (iv) With certain  exceptions,  a public  service  corporation is
          required to obtain  certificates of convenience and necessity from the
          Arizona  Corporation  Commission  under  A.R.S.  Section  40-281.A for
          construction  of  its  lines,  plant,  services,  or  systems,  or any
          extensions  thereof,  within  the  State  of  Arizona,  and to  obtain
          franchises   or  similar   consents  or  permits  from   counties  and
          incorporated  municipalities  under  A.R.S.  Section  40-283.A for the
          construction,  operation, and maintenance of transmission lines within
          the State of Arizona;  to the best of such counsel's  knowledge  after
          due inquiry, the Company holds such valid franchises,  certificates of
          convenience  and  necessity,  consents,  and permits  pursuant to such
          statutory  provisions as are necessary with respect to the maintenance
          and  operation of its property and business as now  conducted,  except
          that (A) the Company from time to time makes minor  extensions  of its
          system prior to the time a related franchise, certificate, license, or
          permit is procured,  (B) from time to time  communities  already being
          served by the Company become  incorporated and  considerable  time may
          elapse before a franchise is procured, (C) certain franchises may have
          expired prior to the renegotiation  thereof, (D) certain minor defects
          and exceptions may exist which, individually and in the aggregate, are
          not deemed  material,  and (E) such  counsel  need not be  required to
          express any opinion regarding the geographical scope of any franchise,
          certificate,  license,  or  permit  that  is  not  specific  as to its
          geographical scope;

               (v) The  issuance  and sale of the  Purchased  Securities  on the
          terms and conditions set forth

                                       8

          or  contemplated  herein and in the Prospectus and the Terms Agreement
          relating to the Purchased Securities and the execution and delivery of
          the Supplemental  Indenture relating to the Purchased  Securities have
          been duly  authorized  by the  Arizona  Corporation  Commission,  said
          Commission had jurisdiction in the premises,  and no further approval,
          authorization,  or  consent  of any  other  public  board  or  body is
          necessary to the validity of such issuance and sale of such  Purchased
          Securities  or  the  execution  and  delivery  of  such   Supplemental
          Indenture,  except as may be required  under state  securities or blue
          sky laws,  as to which  laws such  counsel  shall not be  required  to
          express an opinion;

               (vi) The  Registration  Statement has become  effective under the
          Act, and, to the best of the knowledge of such counsel,  no stop order
          suspending the  effectiveness of the  Registration  Statement has been
          issued and no proceedings for that purpose have been instituted or are
          pending  or  contemplated   under  the  Act,  and  each  part  of  the
          Registration  Statement  relating  to the  Securities,  when such part
          became effective, and the Prospectus, as of the date of the Prospectus
          Supplement,  and each  amendment or  supplement  thereto,  as of their
          respective  effective  or  issue  dates,  complied  as to  form in all
          material  respects  with  the  requirements  of  the  Act,  the  Trust
          Indenture Act, and the published Rules and  Regulations;  such counsel
          has no reason to believe that any part of the Registration  Statement,
          when such part became effective, or the Prospectus,  as of the date of
          the Prospectus Supplement, or as of the Closing Date, or any amendment
          or  supplement  thereto,  as of their  respective  effective  or issue
          dates, or as of the Closing Date,  contained any untrue statement of a
          material  fact or omitted to state any  material  fact  required to be
          stated  therein  or  necessary  to make  the  statements  therein  not
          misleading;   the  descriptions  in  the  Registration  Statement  and
          Prospectus  of  statutes,   legal  and  governmental  proceedings  and
          contracts,  and other  documents  are accurate and fairly  present the
          information required to be shown; and to the actual knowledge of those
          persons in the lawyer group  described in such  opinion,  there are no
          legal or  governmental  proceedings  required to be  described  in the
          Prospectus  that are not  described as required,  nor any contracts or
          documents of a character  required to be described in the Registration
          Statement or Prospectus or to be filed as exhibits to the Registration
          Statement

                                       9

          that are not described and filed as required (it being understood that
          such counsel need express no opinion as to the financial statements or
          other  financial data contained in the  Registration  Statement or the
          Prospectus); and

               (vii)  This  Agreement  and the  Terms  Agreement  have been duly
          authorized, executed, and delivered by the Company.

          In giving such opinion, (a) Snell & Wilmer L.L.P. may rely solely upon
     certificates  of the Company as to any factual  matters upon which any such
     opinions are based and may rely upon the opinion of Keleher & McLeod, P.A.,
     referred to below,  as to all matters  governed by the laws of the State of
     New  Mexico,  but the  opinion of Snell & Wilmer  L.L.P.  shall state that,
     though they are members of the Arizona Bar and do not hold  themselves  out
     as experts on the laws of the State of New  Mexico,  they have made a study
     of the  laws  of such  State  insofar  as such  laws  are  involved  in the
     conclusions  stated  in  their  opinion,  and from  such  study it is their
     opinion that such laws support such conclusions and that, in their opinion,
     the  Underwriters and they are justified to such extent in relying upon the
     opinion of Keleher & McLeod,  P.A.; and (b) the lawyer group referred to in
     such  opinion  will mean  those  lawyers  in the  offices of Snell & Wilmer
     L.L.P. who (i) have billed any time on the particular  transaction to which
     such opinion relates or (ii) have billed more than ten hours to any Company
     matter in the  twelve-month  period preceding the date on which the list of
     such lawyers was compiled for purposes of inquiry pursuant to such opinion.
     In rendering such opinion, Snell & Wilmer L.L.P. may rely as to all matters
     governed  by the laws of the State of New York upon the  opinion of counsel
     for the Underwriters referred to below.

          (e) The  Underwriters  or the  Representatives  shall have received an
     opinion of Keleher & McLeod,  P.A.,  New Mexico  counsel  for the  Company,
     dated the Closing Date, to the effect that:

               (i) The Company is duly qualified as a foreign  corporation to do
          business  and is in good  standing  in the State of New Mexico and has
          full  corporate  power  and  authority  to  engage in the State of New
          Mexico in the business now conducted by it therein; and

               (ii) The  activities of the Company in the State of New Mexico to
          date do not  constitute it a "public  utility" as that term is defined
          in the relevant laws of the State of New Mexico,  and accordingly,  no
          public utility franchises or certificates of convenience and necessity
          are

                                       10

          necessary  under New Mexico law with  respect to the  maintenance  and
          operation of the  Company's  property and business as now conducted in
          the State of New Mexico and no approval,  authorization, or consent of
          the New Mexico Public Regulation  Commission or any other public board
          or body of the State of New Mexico is required  for the  issuance  and
          sale of the Purchased  Securities on the terms and  conditions  herein
          and in the Prospectus set forth or  contemplated  or for the execution
          of the Supplemental  Indenture  relating to the Purchased  Securities,
          except as may be required  under New Mexico state  securities  or blue
          sky laws,  as to which  laws such  counsel  shall not be  required  to
          express an opinion.

     In giving  such  opinion,  Keleher  & McLeod,  P.A.  may rely  solely  upon
     certificates  of the Company as to any factual  matters upon which any such
     opinions are based.

          (f) The Underwriters or the  Representatives  shall have received from
     counsel for the  Underwriters  such opinion or opinions,  dated the Closing
     Date, with respect to the incorporation of the Company, the validity of the
     Purchased Securities, the Registration Statement, the Prospectus, and other
     related  matters as may reasonably be required,  and the Company shall have
     furnished to such counsel such documents as they request for the purpose of
     enabling them to pass upon such matters.  In rendering  such opinion,  such
     counsel  may rely as to the  incorporation  of the  Company  and all  other
     matters  governed  by the laws of the States of Arizona and New Mexico upon
     the opinions of Snell & Wilmer L.L.P. and Keleher & McLeod,  P.A., referred
     to above.

          (g) The  Underwriters  or the  Representatives  shall have  received a
     certificate  of  the  President  or  any  Vice  President  and a  principal
     financial or accounting officer of the Company,  dated the Closing Date, in
     which  such  officers,  to the best of  their  knowledge  after  reasonable
     investigation,  shall state that the  representations and warranties of the
     Company  in this  Agreement  are true and  correct,  that the  Company  has
     complied with all agreements and satisfied all conditions on its part to be
     performed or satisfied at or prior to the Closing Date,  that no stop order
     suspending the effectiveness of the Registration  Statement has been issued
     and  no  proceedings   for  that  purpose  have  been   instituted  or  are
     contemplated  by the  Commission,  and that,  subsequent to the date of the
     most  recent  financial  statements  in the  Prospectus,  there has been no
     material adverse change in the financial  position or results of operations
     of the Company and its subsidiaries  except as set forth or contemplated in
     the Prospectus or as described in such certificate.

                                       11

          (h) The  Underwriters  or the  Representatives  shall have  received a
     letter of DELOITTE & TOUCHE LLP,  dated the Closing  Date,  which meets the
     requirements  of subsection (a) of this Section,  except that the specified
     date referred to in such  subsection will be a date not more than five days
     prior to the Closing Date for the purposes of this subsection.

          The Company will furnish the Underwriters or the Representatives  with
such conformed copies of such opinions, certificates,  letters, and documents as
may be reasonably requested.

     6. INDEMNIFICATION.

          (a) The Company will indemnify and hold harmless each  Underwriter and
     each person,  if any, who controls such  Underwriter  within the meaning of
     the Act  against  any  losses,  claims,  damages or  liabilities,  joint or
     several,  to which such Underwriter or such  controlling  person may become
     subject,  under  the Act or  otherwise,  insofar  as such  losses,  claims,
     damages, or liabilities (or actions in respect thereof) arise out of or are
     based upon any untrue statement or alleged untrue statement of any material
     fact contained in any part of the  Registration  Statement  relating to the
     Securities,  when such part became effective, any preliminary prospectus or
     preliminary  prospectus  supplement,  the  Prospectus,  or any amendment or
     supplement  thereto,  or arise out of or are  based  upon the  omission  or
     alleged  omission to state  therein a material  fact  required to be stated
     therein or necessary to make the  statements  therein not  misleading;  and
     will reimburse each  Underwriter and each such  controlling  person for any
     legal or other  expenses  reasonably  incurred by such  Underwriter or such
     controlling  person in connection with  investigating or defending any such
     loss, claim, damage,  liability,  or action;  provided,  however,  that the
     Company  will not be liable in any such  case to the  extent  that any such
     loss, claim,  damage, or liability arises out of or is based upon an untrue
     statement or alleged untrue  statement or omission or alleged omission made
     in any of such  documents in reliance upon and in  conformity  with written
     information  furnished to the Company by any Underwriter  specifically  for
     use therein.  This indemnity agreement will be in addition to any liability
     which the Company may otherwise have.

          (b) Each  Underwriter  will severally  indemnify and hold harmless the
     Company,  each of its  directors,  each of its officers who have signed the
     Registration  Statement,  and each person, if any, who controls the Company
     within the  meaning of the Act,  against any losses,  claims,  damages,  or
     liabilities  to  which  the  Company  or any  such  director,  officer,  or
     controlling person may become subject, under the Act or otherwise,  insofar
     as such losses,  claims,  damages,  or  liabilities  (or actions in respect
     thereof)  arise out of or are based  upon any untrue  statement  or alleged
     untrue

                                       12

     statement of any material  fact  contained in any part of the  Registration
     Statement relating to the Securities,  when such part became effective, any
     preliminary   prospectus  or   preliminary   prospectus   supplement,   the
     Prospectus,  or any amendment or supplement thereto, or arise out of or are
     based upon the omission or the alleged omission to state therein a material
     fact  required to be stated  therein or  necessary  to make the  statements
     therein not misleading, in each case to the extent, but only to the extent,
     that such  untrue  statement  or alleged  untrue  statement  or omission or
     alleged  omission was made in reliance upon and in conformity  with written
     information  furnished to the Company by such Underwriter  specifically for
     use therein;  and will  reimburse  any legal or other  expenses  reasonably
     incurred  by the  Company or any such  director,  officer,  or  controlling
     person in connection with  investigating or defending any such loss, claim,
     damage,  liability, or action. This indemnity agreement will be in addition
     to any liability which such Underwriter may otherwise have.

          (c) Promptly after receipt by an indemnified  party under this Section
     of notice of the commencement of any action,  such indemnified  party will,
     if a claim in respect thereof is to be made against the indemnifying  party
     under this  Section,  notify  the  indemnifying  party of the  commencement
     thereof;  but the  omission  so to notify the  indemnifying  party will not
     relieve it from any  liability  that it may have to any  indemnified  party
     otherwise  than  under  this  Section.  In case any such  action is brought
     against any indemnified  party, and it notifies the  indemnifying  party of
     the  commencement  thereof,  the  indemnifying  party will be  entitled  to
     participate  therein and, to the extent that it may wish,  jointly with any
     other indemnifying party similarly notified, to assume the defense thereof,
     with counsel satisfactory to such indemnified party (who shall not, without
     the  consent of the  indemnified  party,  be  counsel  to the  indemnifying
     party),  and after notice from the  indemnifying  party to such indemnified
     party of its election so to assume the defense  thereof,  the  indemnifying
     party will not be liable to such  indemnified  party under this Section for
     any legal or other expenses subsequently incurred by such indemnified party
     in  connection  with the defense  thereof  other than  reasonable  costs of
     investigation. An indemnifying party shall not be liable for any settlement
     of a claim or action effected without its written consent,  which shall not
     be unreasonably withheld.

          (d) If the indemnification provided for in this Section is unavailable
     or insufficient to hold harmless an indemnified  party for any loss, claim,
     damage, liability, or action described in subsection (a) or (b) above, then
     each  indemnifying  party shall contribute to the amount paid or payable by
     such  indemnified  party as a result  of the  losses,  claims,  damages  or
     liabilities referred to in subsection (a)

                                       13

     or (b) above on the  following  basis:  (1) if such  loss,  claim,  damage,
     liability,  or action arises under  subsection (a) above,  then (i) in such
     proportion as is appropriate to reflect the relative  benefits  received by
     the  Company  on the one hand and the  Underwriters  on the other  from the
     offering of the Securities or (ii) if the allocation provided by clause (i)
     above  is not  permitted  by  applicable  law,  in  such  proportion  as is
     appropriate to reflect not only the relative benefits referred to in clause
     (i) above but also the  relative  fault of the  Company on the one hand and
     the  Underwriters  on the  other  in  connection  with  the  statements  or
     omissions which resulted in such losses,  claims, damages or liabilities as
     well as any other relevant equitable considerations;  and (2) if such loss,
     claim, damage, liability, or action arises under subsection (b) above, then
     in such  proportion as is  appropriate to reflect the relative fault of the
     Company on the one hand and the Underwriter on the other in connection with
     the statements or omissions which resulted in such losses,  claims, damages
     or liabilities as well as any other relevant equitable considerations.  For
     the  purposes of clause (1) above,  the relative  benefits  received by the
     Company on the one hand and the  Underwriters  on the other shall be deemed
     to be in the same  proportion  as the total net proceeds  from the offering
     (before  deducting  expenses)  received  by the  Company  bear to the total
     underwriting  discounts and commissions  received by the Underwriters.  For
     the  purposes of clauses  (1) and (2) above,  the  relative  fault shall be
     determined  by  reference  to,  among other  things,  whether the untrue or
     alleged  untrue  statement  of a material  fact or the  omission or alleged
     omission to state a material  fact relates to  information  supplied by the
     Company or the  Underwriters and the parties'  relative intent,  knowledge,
     access to  information  and  opportunity  to correct or prevent such untrue
     statement or omission.  The amount paid by an indemnified party as a result
     of the  losses,  claims,  damages or  liabilities  referred to in the first
     sentence  of this  subsection  (d) shall be deemed to include  any legal or
     other expenses  reasonably incurred by such indemnified party in connection
     with investigating or defending any action or claim which is the subject of
     this  subsection  (d).  No person  guilty of  fraudulent  misrepresentation
     (within  the  meaning of Section  11(f) of the Act)  shall be  entitled  to
     contribution  from  any  person  who was  not  guilty  of  such  fraudulent
     misrepresentation.  The Underwriters' obligations in this subsection (d) to
     contribute  are  several in  proportion  to their  respective  underwriting
     obligations and not joint.

     7. DEFAULT OF UNDERWRITERS.  If any Underwriter or Underwriters  default in
their obligations to purchase  Purchased  Securities  pursuant to this Agreement
and the Terms  Agreement and the principal  amount of Purchased  Securities that
such defaulting Underwriter or Underwriters agreed but failed to purchase is ten
percent (10%) or less of the principal amount of Purchased

                                       14

Securities  to which such  Terms  Agreement  relates,  the  Underwriters  or the
Representatives  may  make  arrangements  satisfactory  to the  Company  for the
purchase of such  Purchased  Securities by other  persons,  including any of the
Underwriters,  but if no such  arrangements  are  made by the  Closing  Date the
nondefaulting  Underwriters shall be obligated severally, in proportion to their
respective commitments hereunder and under such Terms Agreement, to purchase the
Purchased Securities that such defaulting Underwriter or Underwriters agreed but
failed to  purchase.  If any  Underwriter  or  Underwriters  so default  and the
aggregate  principal  amount of Purchased  Securities with respect to which such
default  or  defaults  occur  is  more  than  the  above-described   amount  and
arrangements  satisfactory to the remaining Underwriters and the Company for the
purchase  of such  Purchased  Securities  by other  persons  are not made within
thirty-six hours after such default,  the Terms Agreement will terminate without
liability on the part of any non-defaulting  Underwriter or the Company,  except
as  provided  in Section 8. As used in this  Agreement,  the term  "Underwriter"
includes any person  substituted for an Underwriter under this Section.  Nothing
herein will relieve a defaulting Underwriter from liability for its default.

     8. SURVIVAL OF CERTAIN  REPRESENTATIONS  AND  OBLIGATIONS.  The  respective
indemnities,  agreements,  representations,  warranties, and other statements of
the  Company  or its  officers  and of the  Underwriters  set  forth  in or made
pursuant to this  Agreement  will remain in full force and effect  regardless of
any investigation,  or statement as to the results thereof, made by or on behalf
of the  Underwriters  or the Company or any of its  officers or directors or any
controlling  person,  and will survive delivery of and payment for the Purchased
Securities.  If any Terms  Agreement is terminated  pursuant to Section 7, or if
for any reason a purchase  pursuant to any Terms  Agreement is not  consummated,
the Company shall remain  responsible  for the expenses to be paid or reimbursed
by it pursuant to Section 4 and the  respective  obligations  of the Company and
the Underwriters pursuant to Section 6 shall remain in effect.

     9.  NOTICES.  All  communications  hereunder  relating  to any  offering of
Purchased Securities will be in writing,  and, if sent to the Underwriters,  may
be mailed,  delivered,  or telecopied and confirmed to the Representative  first
named in the  Terms  Agreement  relating  to such  Purchased  Securities  or the
Underwriters  at their  addresses  furnished  to the  Company in writing for the
purpose of communications;  provided, however, that any notice to an Underwriter
pursuant to Section 6 will be mailed,  delivered, or telecopied and confirmed to
each such Underwriter at its own address.  All  communications  hereunder to the
Company shall be mailed to the Company, Attention: Treasurer, at P.O. Box 53999,
Phoenix,  Arizona 85O72-3999,  or delivered,  or telecopied and confirmed to the
Company at 400 North Fifth Street, Phoenix, Arizona 85004.

                                       15

     10. SUCCESSORS.  This Agreement will inure to the benefit of and be binding
upon the parties hereto and the  Underwriter or Underwriters as are named in any
Terms Agreement and their  respective  successors and the officers and directors
and controlling  persons referred to in Section 6, and no other person will have
any right or obligation hereunder.

     11.  REPRESENTATION OF UNDERWRITERS.  The Representatives,  if any, may act
for the  Underwriters in connection with any offering to which a Terms Agreement
may relate, and any action under this Agreement or such Terms Agreement taken by
the  Representatives  jointly or the  Representative  first  named in such Terms
Agreement in such  capacity will be binding upon the  Underwriters  of Purchased
Securities to which such Terms Agreement relates.

     12. EXECUTION IN COUNTERPART. This Agreement and any Terms Agreement may be
executed  in one or more  counterparts,  each of which  shall be deemed to be an
original,  but all such  respective  counterparts  shall  together  constitute a
single instrument.

                                       16

     If the foregoing is in accordance with your understanding of our agreement,
kindly sign and return to us the enclosed  duplicate  hereof,  whereupon it will
become  a  binding  agreement  between  the  Company  and  the  Underwriters  in
accordance with its terms.


                                            Very truly yours,

                                            ARIZONA PUBLIC SERVICE COMPANY



                                            By Barbara M. Gomez
                                               ---------------------------------
                                                            Treasurer



The foregoing  Underwriting Agreement
is hereby confirmed and accepted as
of the date first above written.

CHASE SECURITIES INC.


By William Dexter Rogers
   -----------------------------------
            Managing Director


CREDIT SUISSE FIRST BOSTON CORPORATION


By Reginald O. Frazier
   -----------------------------------
               Director

SALOMON SMITH BARNEY INC.


By Howard Hiller
   -----------------------------------
            Managing Director

                                       17


                                 TERMS AGREEMENT


                                                                November 2, 1999

Arizona Public Service Company
400 North Fifth Street
Phoenix, Arizona 85004

Attention:  Treasurer

Dear Madam:

     Arizona Public Service Company (the "Company") hereby agrees to sell to the
several  Underwriters (the  "Underwriters")  listed in the Company's  Prospectus
Supplement  (the  "Prospectus  Supplement")  of even date  herewith  relating to
$250,000,000 in aggregate  principal  amount of its Floating Rate Notes Due 2001
(the "Purchased  Securities"),  and the  Underwriters  hereby agree to purchase,
severally and not jointly, at a purchase price of 99.80% of the principal amount
thereof  plus any  accrued  interest  from the date of  original  issuance,  the
respective  principal  amounts of Purchased  Securities  set forth  opposite the
names  of the  Underwriters  in  the  Prospectus  Supplement.  The  sale  of the
Purchased Securities by the Company and the purchase thereof by the Underwriters
shall be made on the basis of the  representations,  warranties,  and agreements
contained in the Underwriting  Agreement (the "Underwriting  Agreement"),  dated
November 2, 1999, relating to the issuance and sale of up to $275,000,000 of the
Company's Securities under the Company's Indenture,  and shall be subject to the
terms and conditions set forth in such Underwriting Agreement. The provisions of
the Underwriting Agreement are incorporated herein by reference. As contemplated
by  Section 3 of the  Underwriting  Agreement,  certain  terms of the  Purchased
Securities are described in the Prospectus Supplement.

     The Underwriters propose to offer the Purchased Securities to the public in
the manner and upon the terms set out in the Prospectus Supplement.

     On November 8, 1999 the Company will deliver the  Purchased  Securities  to
the  Underwriters  in book-entry  form through the  facilities of The Depository
Trust  Company at the office of the Company,  400 North Fifth  Street,  Phoenix,
Arizona 85004, against payment of the purchase price by transfer of funds by Fed
Wire  from the  Underwriters  to the  Company's  account  at a bank in  Phoenix,
Arizona  designated by the Company.  Such purchase  price will be deemed to have
been  received  by the  Company  upon  the  Company's  receipt  of the Fed  Wire
reference number relating to such transfer of funds.  Closing shall occur at the
office of the Company,  400 North Fifth Street,  Phoenix,  Arizona, at 8:00 a.m.
Phoenix  time,  on  November  8,  1999,  or at such  other  time and date as the
Underwriters and the Company may agree upon in writing, such time and date being
referred to as the "Closing Date." All of the Purchased  Securities  referred to
in this  paragraph  shall be in global form and registered in the name of Cede &
Co. and deposited with The Depository Trust Company, as depositary.

     If the  foregoing  is  acceptable  to you,  please sign below and  transmit
evidence of such signing to Chase Securities Inc. at your earliest  convenience.
At that  point,  the  agreement  signified  hereby  will  constitute  the  Terms
Agreement,  as  described  in the  Underwriting  Agreement,  with respect to the
$250,000,000 of Purchased Securities referred to herein.

     All capitalized  terms herein,  not otherwise  defined herein,  are used as
defined in the Underwriting Agreement.  This agreement may be executed in one or
more counterparts, each of which shall be deemed to be an original, but all such
respective counterparts shall together constitute a single instrument.


                                         Very truly yours,

                                         CHASE SECURITIES INC.
                                         CREDIT SUISSE FIRST BOSTON CORPORATION
                                         SALOMON SMITH BARNEY INC.

                                         By:   CHASE SECURITIES INC.
                                               (As Representative of the
                                               Several Underwriters)


                                               By William Dexter Rogers
                                                  ------------------------------
                                                         Managing Director

Confirmed and accepted as of
the date first above written.

ARIZONA PUBLIC SERVICE COMPANY


By Barbara M. Gomez
   ---------------------------------
    Treasurer