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                         ARIZONA PUBLIC SERVICE COMPANY

                                       TO

                            THE CHASE MANHATTAN BANK

                                     Trustee

                          First Supplemental Indenture

                          Dated as of January 15, 1998

                                       To

                                    Indenture

                          Dated as of January 15, 1998

                              --------------------


                              6 1/4% Notes Due 2005

                  ---------------------------------------------

         FIRST  SUPPLEMENTAL  INDENTURE,  dated as of January 15, 1998,  between
Arizona Public Service Company,  a corporation duly organized and existing under
the laws of the State of  Arizona  (herein  called  the  "Company"),  having its
principal  office at 400 North Fifth Street,  Phoenix,  Arizona  85004,  and The
Chase Manhattan Bank, a New York banking corporation,  as Trustee (herein called
the  "Trustee")  under the  Indenture  dated as of January 15, 1998  between the
Company and the Trustee (the "Indenture").

                             RECITALS OF THE COMPANY

         The Company has executed and  delivered the Indenture to the Trustee to
provide for the issuance from time to time of its unsecured debentures, notes or
other evidences of indebtedness (the "Securities"), said Securities to be issued
in one or more series as in the Indenture provided.

         Pursuant to the terms of the Indenture,  the Company desires to provide
for the  establishment  of a new series of its  Securities  to be known as its 6
1/4% Notes Due 2005 (herein called the "Notes Due 2005"), the form and substance
of such Notes Due 2005 and the terms,  provisions,  and conditions thereof to be
set forth as provided in the Indenture and this First Supplemental Indenture.

         All things necessary to make this First Supplemental  Indenture a valid
agreement of the Company,  and to make the Notes Due 2005,  when executed by the
Company and authenticated and delivered by the Trustee, the valid obligations of
the Company, have been done.

          NOW, THEREFORE, THIS FIRST SUPPLEMENTAL INDENTURE WITNESSETH:

         For and in  consideration of the premises and the purchase of the Notes
Due 2005 by the  Holders  thereof,  and for the  purpose  of setting  forth,  as
provided in the Indenture,  the form and substance of the Notes Due 2005 and the
terms, provisions,  and conditions thereof, it is mutually agreed, for the equal
and proportionate benefit of all Holders of the Notes Due 2005, as follows:

                                   ARTICLE ONE

                         GENERAL TERMS AND CONDITIONS OF
                               THE NOTES DUE 2005

         SECTION  101.  There  shall be and is  hereby  authorized  a series  of
Securities designated the "6 1/4% Notes Due 2005" limited in aggregate principal
amount to $100,000,000,  which amount shall be as set forth in any Company Order
for the  authentication and delivery of Notes Due 2005. The Notes Due 2005 shall
mature and the principal shall be due and payable  together with all accrued and
unpaid interest  thereon on January 15, 2005, and shall be issued in the form of
registered Notes Due 2005 without coupons.
                                       2

         SECTION 102. The Notes Due 2005 shall be issued in  certificated  form,
except that the Notes Due 2005 shall be issued initially as a Global Security to
and  registered  in the name of Cede & Co., as nominee of The  Depository  Trust
Company, as Depositary therefor.  Any Notes Due 2005 to be issued or transferred
to, or to be held by, Cede & Co. (or any  successor  thereof)  for such  purpose
shall bear the depositary  legend in substantially the form set forth at the top
of the form of Note Due 2005 in Article Two hereof (in lieu of that set forth in
Section 204 of the  Indenture),  unless  otherwise  agreed by the Company,  such
agreement to be confirmed in writing to the Trustee. Such Global Security may be
exchanged in whole or in part for Notes Due 2005 registered, and any transfer of
such Global Security in whole or in part may be registered, in the name or names
of  Persons  other  than such  Depositary  or a nominee  thereof  only under the
circumstances  set forth in Clause (2) of the last  paragraph  of Section 305 of
the Indenture,  or such other  circumstances  in addition to or in lieu of those
set forth in Clause (2) of the last paragraph of Section 305 of the Indenture as
to which the Company shall agree,  such  agreement to be confirmed in writing to
the Trustee.  Principal  of, and premium,  if any, and interest on the Notes Due
2005 will be payable,  the  transfer of Notes Due 2005 will be  registrable  and
Notes Due 2005 will be exchangeable  for Notes Due 2005 bearing  identical terms
and  provisions,  at the  office or  agency of the  Company  in the  Borough  of
Manhattan,  The City and State of New York; provided,  however,  that payment of
interest  may be made at the  option  of the  Company  by  check  mailed  to the
registered holder at such address as shall appear in the Security Register.

         SECTION  103.  Each Note Due 2005 will bear  interest  at the rate of 6
1/4% per annum from  January 16, 1998 or from the most recent  Interest  Payment
Date (as  hereinafter  defined) to which interest has been paid or duly provided
for until the principal  thereof is paid or made available for payment,  payable
on January  15 and July 15 of each year  (each,  an  "Interest  Payment  Date"),
commencing  on July 15, 1998,  to the person in whose name such Note Due 2005 or
any Predecessor Security is registered,  at the close of business on the January
1 or July 1 next  preceding  such  Interest  Payment  Date.  Any  such  interest
installment not punctually paid or duly provided for shall forthwith cease to be
payable to the  registered  holders on such regular record date, and may be paid
to the  person  in whose  name  the  Note  Due 2005 (or one or more  Predecessor
Securities)  is registered at the close of business on a special  record date to
be fixed by the  Trustee  for the  payment of such  defaulted  interest,  notice
whereof shall be given to the registered  holders of the Notes Due 2005 not less
than 10 days prior to such special  record  date,  or may be paid at any time in
any other lawful manner not inconsistent with the requirements of any securities
exchange on which the Notes Due 2005 may be listed,  and upon such notice as may
be required by such exchange, all as more fully provided in the Indenture.

         The amount of  interest  payable for any period will be computed on the
basis of a 360-day  year of twelve  30-day  months.  Interest  will  accrue from
January 16, 1998 to, but not including,  the relevant payment date. In the event
that  any date on which  interest  is  payable  on the  Notes  Due 2005 is not a
Business Day, then payment of interest  payable on such date will be made on the
next  succeeding  day which is a Business Day (and without any interest or other
payment  in  respect  of any such  delay),  in each case with the same force and
effect as if made on such date. 
                                       3

A  "Business  Day"  shall  mean  any  day  other  than  a day on  which  banking
institutions  in The City of New  York are  authorized  or  obligated  by law or
executive order to close.

         SECTION 104. The Company,  at its option,  at any time, may redeem all,
or, from time to time,  any part of the Notes Due 2005,  upon notice as provided
in the  Indenture  at a redemption  price equal to the sum of (a) the  principal
amount of the Notes Due 2005 (or portion  thereof)  being  redeemed plus accrued
interest  thereon to the redemption date and (b) the Make-Whole  Amount (if any)
with respect to the Notes Due 2005 being redeemed.

         For purposes of this Section  104, the  following  terms shall have the
following meanings:

         "Make-Whole  Amount" means, in connection with any optional  redemption
of any Notes Due 2005,  the excess,  if any, of (i) the sum, as  determined by a
Quotation  Agent (as  defined  herein) of the  present  values of the  principal
amount of such Notes Due 2005,  together  with  scheduled  payments  of interest
(exclusive of interest to the date of redemption)  from the  redemption  date to
the Maturity of the Notes Due 2005, in each case  discounted  to the  redemption
date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day
months) at the Adjusted  Treasury Rate (as defined herein) over (ii) 100% of the
principal amount of the Notes Due 2005 to be redeemed.

         "Adjusted  Treasury Rate" means,  with respect to any redemption  date,
the rate per annum equal to the semi-annual  equivalent yield to maturity of the
Comparable Treasury Issue,  calculated using a price for the Comparable Treasury
Issue  (expressed  as a  percentage  of  its  principal  amount)  equal  to  the
Comparable  Treasury  Price for such  redemption  date,  calculated on the third
Business Day preceding the  redemption  date,  plus in each case 0.15% (15 basis
points).

         "Comparable  Treasury Issue" means the United States Treasury  security
selected by the Quotation Agent as having a maturity comparable to the remaining
term from the  redemption  date to the Maturity of the Notes Due 2005 that would
be utilized, at the time of selection and in accordance with customary financial
practice,  in pricing new issues of  corporate  debt  securities  of  comparable
maturity to the remaining term of the Notes Due 2005.

         "Quotation  Agent" means the Reference  Treasury Dealer selected by the
Trustee after consultation with the Company. "Reference Treasury Dealer" means a
primary U.S. Government securities dealer selected by the Company.

         "Comparable Treasury Price" means, with respect to any redemption date,
(i) the average of the bid and asked prices for the  Comparable  Treasury  Issue
(expressed in each case as a percentage  of its  principal  amount) on the third
Business  Day  preceding  such  redemption  date,  as set  forth  in  the  daily
statistical  release (or any successor release) published by the Federal Reserve
Bank of New  York  and  designated  "Composite  3:30  p.m.  Quotations  for U.S.
Government Securities" or (ii) if such release (or any successor release) is not
published or does 
                                       4

not contain  such  prices on such  Business  Day,  the average of three (or such
lesser  number  as  is  obtained  by  the  Trustee)  Reference  Treasury  Dealer
Quotations for such redemption date.

         "Reference  Treasury  Dealer  Quotations"  means,  with respect to each
Reference Treasury Dealer and any redemption date, the average, as determined by
the  Trustee,  of the bid and asked  prices for the  Comparable  Treasury  Issue
(expressed  in each case as a  percentage  of its  principal  amount)  quoted in
writing to the Trustee by such Reference  Treasury Dealer at 5:00 p.m., New York
City time, on the third Business Day preceding such redemption date.

         The Trustee  shall be under no duty to inquire into,  may  conclusively
presume  the  correctness  of, and shall be fully  protected  in acting upon the
Company's  calculation of any Redemption Price,  including any Make-Whole Amount
(if any).

         The Company  shall give the Trustee  written  notice of the  Redemption
Price, promptly after the calculation thereof.

         Notwithstanding Section 1104 of the Indenture, any notice of redemption
given pursuant to said Section with respect to the foregoing redemption need not
set forth the Redemption Price but only the manner of calculation thereof.

         SECTION 105. The Notes Due 2005 shall be defeasible pursuant to Section
1302 and Section 1303 of the Indenture.

                                   ARTICLE TWO

                             FORM OF NOTES DUE 2005

         SECTION  201.  The  Notes  Due 2005 and the  Trustee's  certificate  of
authentication  to be endorsed  thereon are to be substantially in the following
forms:

Form of Face of Security:

UNLESS THIS  CERTIFICATE  IS PRESENTED BY AN  AUTHORIZED  REPRESENTATIVE  OF THE
DEPOSITORY  TRUST COMPANY,  A NEW YORK  CORPORATION  ("DTC"),  TO ARIZONA PUBLIC
SERVICE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE, OR PAYMENT,
AND ANY  CERTIFICATE  ISSUED IS  REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH
OTHER  NAME AS IS  REQUESTED  BY AN  AUTHORIZED  REPRESENTATIVE  OF DTC (AND ANY
PAYMENT  IS MADE TO CEDE & CO. OR TO SUCH  OTHER  ENTITY AS IS  REQUESTED  BY AN
AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR
VALUE OR  OTHERWISE BY OR TO ANY PERSON IS WRONGFUL  INASMUCH AS THE  REGISTERED
OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.
                                       5

                         ARIZONA PUBLIC SERVICE COMPANY

                              6 1/4% Note Due 2005

No. _________                                                       $100,000,000
                                                             CUSIP No. 040555BV5

         Arizona  Public  Service  Company,  a  corporation  duly  organized and
existing  under the laws of Arizona  (herein  called the  "Company",  which term
includes any successor Person under the Indenture  hereinafter referred to), for
value received, hereby promises to pay to Cede & Co., or registered assigns, the
principal  sum of One Hundred  Million  Dollars on January 15, 2005,  and to pay
interest  thereon from January 16, 1998 or from the most recent Interest Payment
Date to which  interest has been paid or duly  provided  for,  semi-annually  on
January 15 and July 15 in each year,  commencing July 15, 1998, at the rate of 6
1/4% per  annum,  until  the  principal  hereof  is paid or made  available  for
payment.  The interest so payable,  and punctually paid or duly provided for, on
any Interest  Payment Date will, as provided in such  Indenture,  be paid to the
Person in whose name this Security (or one or more  Predecessor  Securities)  is
registered  at the  close  of  business  on the  Regular  Record  Date  for such
interest,  which  shall be the  January 1 or July 1  (whether  or not a Business
Day), as the case may be, next  preceding  such Interest  Payment Date. Any such
interest not so punctually  paid or duly provided for will forthwith cease to be
payable to the Holder on such Regular  Record Date and may either be paid to the
Person in whose name this Security (or one or more  Predecessor  Securities)  is
registered at the close of business on a Special  Record Date for the payment of
such  Defaulted  Interest to be fixed by the Trustee,  notice  whereof  shall be
given to Holders  of  Securities  of this  series not less than 10 days prior to
such Special  Record Date, or be paid at any time in any other lawful manner not
inconsistent  with the  requirements  of any  securities  exchange  on which the
Securities of this series may be listed, and upon such notice as may be required
by such exchange, all as more fully provided in said Indenture.

         Payment of the principal of (and  premium,  if any) and any interest on
this Security will be made at the office or agency of the Company maintained for
that  purpose in The City of New York,  in such coin or  currency  of the United
States of  America as at the time of  payment  is legal  tender  for  payment of
public and private debts;  provided,  however, that at the option of the Company
payment of  interest  may be made by check  mailed to the  address of the Person
entitled thereto as such address shall appear in the Security Register.

         Reference is hereby made to the further provisions of this Security set
forth on the reverse  hereof,  which further  provisions  shall for all purposes
have the same effect as if set forth at this place.

         Unless the  certificate of  authentication  hereon has been executed by
the Trustee referred to on the reverse hereof by manual signature, this Security
shall  not be  entitled  to any  benefit  under  the  Indenture  or be  valid or
obligatory for any purpose.
                                       6

         IN WITNESS  WHEREOF,  the Company has caused this instrument to be duly
executed under its corporate seal.

                                       ARIZONA PUBLIC SERVICE COMPANY


                                       By
                                         ---------------------------------------

Attest:


- ------------------------------

Form of Reverse of Security.

         This  Security is one of a duly  authorized  issue of securities of the
Company (herein called the "Securities"), issued and to be issued in one or more
series  under an  Indenture,  dated as of January  15, 1998  (herein  called the
"Indenture",  which  term  shall  have  the  meaning  assigned  to  it  in  such
instrument),  between  the  Company  and The Chase  Manhattan  Bank,  as Trustee
(herein  called the "Trustee",  which term includes any successor  trustee under
the Indenture), and reference is hereby made to the Indenture for a statement of
the respective rights,  limitations of rights,  duties and immunities thereunder
of the Company,  the Trustee and the Holders of the  Securities and of the terms
upon which the Securities are, and are to be, authenticated and delivered.  This
Security  is  one of the  series  designated  on the  face  hereof,  limited  in
aggregate principal amount to $100,000,000.

         The  Securities of this series are subject to redemption  upon not less
than 30 days' notice by mail at any time at the option of the Company,  in whole
or from time to time in part, at a redemption  price equal to the sum of (i) the
principal  amount of the  Securities  (or portion  thereof)  being redeemed plus
accrued interest  thereon to the redemption date and (ii) the Make-Whole  Amount
(as defined below),  if any, with respect to the Securities  being redeemed (the
"Redemption Price") .

         If notice has been given as provided in the Indenture and funds for the
redemption of any  Securities  (or any portion  thereof)  called for  redemption
shall  have been made  available  on the  redemption  date  referred  to in such
notice,  such Securities (or any portion thereof) will cease to bear interest on
the date fixed for such  redemption  specified in such notice and the only right
of the Holders of such  Securities  will be to receive payment of the Redemption
Price.

         Notice of any optional  redemption of Securities of this series (or any
portion  thereof) will be given to Holders at their  addresses,  as shown in the
Security  Register for such  Securities,  not more than 60 nor less than 30 days
prior to the date fixed for  redemption.  The notice of redemption will specify,
among other items, the Redemption Price or, if not then known, the
                                        7

manner of calculation  thereof,  and the principal amount of the Securities held
by such  Holder to be  redeemed.  If less than all of the  Securities  are to be
redeemed at the option of the Company,  the Trustee shall select, in such manner
as it shall deem fair and  appropriate,  the  portion of such  Securities  to be
redeemed in whole or in part.

         As used herein:

         "Make-Whole  Amount" means, in connection with any optional  redemption
of any  Securities  of this  series,  the  excess,  if any,  of (i) the sum,  as
determined by a Quotation  Agent (as defined  herein),  of the present values of
the principal  amount of such  Securities,  together with scheduled  payments of
interest  (exclusive of interest to the date of redemption)  from the redemption
date  to the  Maturity  of  such  Securities,  in each  case  discounted  to the
redemption  date on a semi-annual  basis  (assuming a 360-day year consisting of
twelve 30-day  months) at the Adjusted  Treasury  Rate (as defined  herein) over
(ii)  100% of the  principal  amount  of the  Securities  of this  series  to be
redeemed.

         "Adjusted  Treasury Rate" means,  with respect to any redemption  date,
the rate per annum equal to the semi-annual  equivalent yield to maturity of the
Comparable Treasury Issue,  calculated using a price for the Comparable Treasury
Issue  (expressed  as a  percentage  of  its  principal  amount)  equal  to  the
Comparable  Treasury  Price for such  redemption  date,  calculated on the third
Business Day preceding the  redemption  date,  plus in each case 0.15% (15 basis
points).

         "Comparable  Treasury Issue" means the United States Treasury  security
selected by the Quotation Agent as having a maturity comparable to the remaining
term from the  redemption  date to the Maturity of the Securities of this series
that  would  be  utilized,  at the  time of  selection  and in  accordance  with
customary financial practice, in pricing new issues of corporate debt securities
of comparable maturity to the remaining term of the Securities of this series.

         "Quotation  Agent" means the Reference  Treasury Dealer selected by the
Trustee after consultation with the Company. "Reference Treasury Dealer" means a
primary U.S. Government securities dealer selected by the Company.

         "Comparable Treasury Price" means, with respect to any redemption date,
(i) the average of the bid and asked prices for the  Comparable  Treasury  Issue
(expressed in each case as a percentage  of its  principal  amount) on the third
Business  Day  preceding  such  redemption  date,  as set  forth  in  the  daily
statistical  release (or any successor release) published by the Federal Reserve
Bank of New  York  and  designated  "Composite  3:30  p.m.  Quotations  for U.S.
Government Securities" or (ii) if such release (or any successor release) is not
published or does not contain such prices on such  Business  Day, the average of
three (or such lesser number as is obtained by the Trustee)  Reference  Treasury
Dealer Quotations for such redemption date.
                                       8

         "Reference  Treasury  Dealer  Quotations"  means,  with respect to each
Reference Treasury Dealer and any redemption date, the average, as determined by
the  Trustee,  of the bid and asked  prices for the  Comparable  Treasury  Issue
(expressed  in each case as a  percentage  of its  principal  amount)  quoted in
writing to the Trustee by such Reference  Treasury Dealer at 5:00 p.m., New York
City time, on the third Business Day preceding such redemption date.

         The Securities of this series will not be subject to any sinking fund.

         In the  event  of  redemption  of this  Security  in part  only,  a new
Security  or  Securities  of this  series and of like  tenor for the  unredeemed
portion  hereof  will be  issued  in the  name of the  Holder  hereof  upon  the
cancellation hereof.

         The Indenture  contains  provisions  for  defeasance at any time of the
entire indebtedness of this Security or certain restrictive covenants and Events
of Default  with respect to this  Security,  in each case upon  compliance  with
certain conditions set forth in the Indenture.

         If an Event of Default with respect to  Securities of this series shall
occur and be  continuing,  the principal of the Securities of this series may be
declared  due and  payable in the manner  and with the  effect  provided  in the
Indenture.

         The Indenture permits, with certain exceptions as therein provided, the
amendment  thereof and the  modification  of the rights and  obligations  of the
Company  and the rights of the  Holders of the  Securities  of each series to be
affected under the Indenture at any time by the Company and the Trustee with the
consent of the Holders of 662/3% in principal  amount of the  Securities  at the
time  Outstanding  of each series to be affected.  The  Indenture  also contains
provisions  permitting the Holders of specified  percentages in principal amount
of the  Securities  of each  series  at the time  Outstanding,  on behalf of the
Holders of all  Securities  of such series,  to waive  compliance by the Company
with certain  provisions of the  Indenture  and certain past defaults  under the
Indenture  and their  consequences.  Any such consent or waiver by the Holder of
this  Security  shall be  conclusive  and binding  upon such Holder and upon all
future Holders of this Security and of any Security issued upon the registration
of transfer  hereof or in  exchange  herefor or in lieu  hereof,  whether or not
notation of such consent or waiver is made upon this Security.

         As provided  in and subject to the  provisions  of the  Indenture,  the
Holder of this  Security  shall not have the right to institute  any  proceeding
with respect to the Indenture or for the appointment of a receiver or trustee or
for any other remedy thereunder,  unless such Holder shall have previously given
the Trustee written notice of a continuing  Event of Default with respect to the
Securities of this series,  the Holders of not less than 25% in principal amount
of the Securities of this series at the time Outstanding shall have made written
request to the  Trustee  to  institute  proceedings  in respect of such Event of
Default as Trustee and offered the Trustee reasonable indemnity, and the Trustee
shall not have  received  from the Holders of a majority in principal  amount of
Securities of this series at the time Outstanding a direction  inconsistent with
                                       9

such  request,  and shall have failed to institute any such  proceeding,  for 60
days after receipt of such notice, request and offer of indemnity. The foregoing
shall not apply to any suit  instituted  by the Holder of this  Security for the
enforcement of any payment of principal hereof or any premium or interest hereon
on or after the respective due dates expressed herein.

         No reference  herein to the Indenture and no provision of this Security
or of the Indenture  shall alter or impair the obligation of the Company,  which
is  absolute  and  unconditional,  to pay the  principal  of and any premium and
interest  on this  Security  at the  times,  place and rate,  and in the coin or
currency, herein prescribed.

         As provided in the Indenture and subject to certain limitations therein
set  forth,  the  transfer  of this  Security  is  registrable  in the  Security
Register,  upon surrender of this Security for  registration  of transfer at the
office or agency of the  Company  in any place  where the  principal  of and any
premium  and  interest  on this  Security  are  payable,  duly  endorsed  by, or
accompanied  by a written  instrument  of transfer in form  satisfactory  to the
Company and the Security  Registrar  duly  executed by, the Holder hereof or his
attorney duly authorized in writing, and thereupon one or more new Securities of
this  series and of like tenor,  of  authorized  denominations  and for the same
aggregate  principal  amount,  will be issued to the  designated  transferee  or
transferees.

         The  Securities  of this series are issuable  only in  registered  form
without coupons in denominations of $1,000 and any integral multiple thereof. As
provided in the Indenture and subject to certain  limitations therein set forth,
Securities of this series are exchangeable for a like aggregate principal amount
of  Securities  of this  series  and of like  tenor  of a  different  authorized
denomination, as requested by the Holder surrendering the same.

         No service charge shall be made for any such  registration  of transfer
or exchange,  but the Company may require  payment of a sum  sufficient to cover
any tax or other governmental charge payable in connection therewith.

         Prior to due presentment of this Security for registration of transfer,
the  Company,  the Trustee and any agent of the Company or the Trustee may treat
the Person in whose name this Security is registered as the owner hereof for all
purposes,  whether or not this Security be overdue, and neither the Company, the
Trustee nor any such agent shall be affected by notice to the contrary.

         All terms used in this  Security  which are  defined  in the  Indenture
shall have the meanings assigned to them in the Indenture.
                                       10

Form of Trustee's Certificate of Authentication.

                          CERTIFICATE OF AUTHENTICATION

         This is one of the Securities of the series designated therein referred
to in the within-mentioned Indenture.

                                                        THE CHASE MANHATTAN BANK
                                                                      As Trustee


                                                        By
                                                          ----------------------
                                                              Authorized Officer


                                  ARTICLE THREE

                        ORIGINAL ISSUE OF NOTES DUE 2005

         SECTION  301.  Notes  Due 2005 in the  aggregate  principal  amount  of
$100,000,000 may, upon execution of this First Supplemental  Indenture,  or from
time to time thereafter, be executed by the Company and delivered to the Trustee
for  authentication,  and the Trustee shall thereupon  authenticate  and deliver
said Notes Due 2005 in accordance  with a Company Order delivered to the Trustee
by the Company, without any further action by the Company.

                                  ARTICLE FOUR

                           PAYING AGENT AND REGISTRAR

         SECTION  401.  The Chase  Manhattan  Bank will be the Paying  Agent and
Security Registrar for the Notes Due 2005.

                                  ARTICLE FIVE

                                SUNDRY PROVISIONS

         SECTION  501.  Except as  otherwise  expressly  provided  in this First
Supplemental  Indenture  or in the form of Notes Due 2005 or  otherwise  clearly
required by the context hereof or thereof, all terms used herein or in said form
of Notes Due 2005 that are  defined  in the  Indenture  shall  have the  several
meanings respectively assigned to them thereby.
                                       11

         SECTION 502. The Indenture,  as supplemented by this First Supplemental
Indenture,   is  in  all  respects  ratified  and  confirmed,   and  this  First
Supplemental  Indenture  shall be deemed part of the Indenture in the manner and
to the extent herein and therein provided.

         SECTION 503. The Trustee  hereby  accepts the trusts  herein  declared,
provided, created,  supplemented, or amended and agrees to perform the same upon
the terms and conditions herein and in the Indenture, as heretofore supplemented
and amended, set forth and upon the following terms and conditions:

         The Trustee shall not be responsible in any manner whatsoever for or in
respect of the validity or sufficiency of this First  Supplemental  Indenture or
for or in respect of the recitals  contained  herein,  all of which recitals are
made by the  Company  solely.  In  general,  each and every  term and  condition
contained in Article Six of the Indenture shall apply to and form a part of this
First Supplemental  Indenture with the same force and effect as if the same were
herein set forth in full with such omissions,  variations,  and  insertions,  if
any, as may be  appropriate  to make the same conform to the  provisions of this
First Supplemental Indenture.

                       ---------------------------------

         This instrument may be executed in any number of counterparts,  each of
which so executed shall be deemed to be an original,  but all such  counterparts
shall together constitute but one and the same instrument.
                                       12

         IN  WITNESS  WHEREOF,   the  parties  hereto  have  caused  this  First
Supplemental Indenture to be duly executed, and their respective corporate seals
to be  hereunto  affixed  and  attested,  all as of the day and year first above
written.

                                           ARIZONA PUBLIC SERVICE COMPANY


                                           By:    Michael V. Palmeri
                                              ----------------------------------
                                                  Michael V. Palmeri
                                                  Treasurer


Attest:

     Betsy A. Pregulman
- -----------------------------------
     Associate Secretary

                                           THE CHASE MANHATTAN BANK, as Trustee


                                           By:    T. J. Foley
                                              ----------------------------------
                                                  Vice President

Attest:

     R. Loren Zen
- -----------------------------------
     Senior Trust Officer
                                       13

STATE OF ARIZONA                    )
                                    ) ss.:
COUNTY OF MARICOPA                  )

         On the 15th day of January,  1998, before me personally came Michael V.
Palmeri, to me known, who, being by me duly sworn, did depose and say that he is
the  Treasurer  of  Arizona  Public  Service  Company,  one of the  corporations
described in and which executed the foregoing instrument; that he knows the seal
of said corporation;  that the seal affixed to said instrument is such corporate
seal;  that it was so affixed by  authority  of the Board of  Directors  of said
corporation; and that he signed his name thereto by like authority.


                                        Linda G. Redman
                                        ---------------
                                        Linda G. Redman
                                        My Commission Expires Feb. 8, 1999




STATE OF NEW YORK                   )
                                    ) ss.:
COUNTY OF NEW YORK                  )

         On the 14th day of  January,  1998,  before  me  personally  came T. J.
Foley, to me known,  who, being by me duly sworn,  did depose and say that he is
Vice President of The Chase Manhattan Bank, one of the corporations described in
and which  executed  the  foregoing  instrument;  that he knows the seal of said
corporation;  that the seal affixed to said  instrument is such corporate  seal;
that  it was so  affixed  by  authority  of  the  Board  of  Directors  of  said
corporation; and that he signed his name thereto by like authority.


                                        Annabelle DeLuca
                                        ----------------
                                        Annabelle DeLuca
                                        Commission expires July 15, 1999
                                       14