EXHIBIT 4(d)

                       PUBLIC SERVICE COMPANY OF OKLAHOMA


                                       and


                              THE BANK OF NEW YORK,
                                   AS TRUSTEE


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


                          FIRST SUPPLEMENTAL INDENTURE

                          Dated as of November 1, 2000


                          Supplemental to the Indenture
                          dated as of November 1, 2000





                     Floating Rate Notes, Series A, Due 2002




      FIRST SUPPLEMENTAL INDENTURE, dated as of November 1, 2000, between PUBLIC
SERVICE COMPANY OF OKLAHOMA, a corporation duly organized and existing under the
laws of the State of Oklahoma (the  "Company"),  and THE BANK OF NEW YORK, a New
York banking  corporation  organized and existing under the laws of the State of
New York,  as  Trustee  under the  Original  Indenture  referred  to below  (the
"Trustee").

                             RECITALS OF THE COMPANY

      The  Company  has  heretofore  executed  and  delivered  to the Trustee an
indenture  dated as of November 1, 2000 (the "Original  Indenture"),  to provide
for the issuance from time to time of its  debentures,  notes or other evidences
of  indebtedness  (the  "Senior  Notes"),  the form and terms of which are to be
established as set forth in Section 201 and 301 of the Original Indenture.

      Section 901 of the Original Indenture  provides,  among other things, that
the  Company  and the  Trustee  may enter into  indentures  supplemental  to the
Original Indenture for, among other things, the purpose of establishing the form
and terms of the Senior Notes of any series as permitted in Sections 201 and 301
of the Original Indenture.

      The Company desires to create a series of the Senior Notes in an aggregate
principal  amount of  $106,000,000  to be designated  the "Floating  Rate Notes,
Series A, Due 2002" (the "Floating  Rate Notes"),  and all action on the part of
the Company necessary to authorize the issuance of the Floating Rate Notes under
the  Original  Indenture  and this First  Supplemental  Indenture  has been duly
taken.

      All acts and  things  necessary  to make the  Floating  Rate  Notes,  when
executed  by the Company  and  completed,  authenticated  and  delivered  by the
Trustee as  provided  in the  Original  Indenture  and this  First  Supplemental
Indenture,  the valid and binding  obligations  of the Company and to constitute
these  presents  a  valid  and  binding  supplemental  indenture  and  agreement
according to its terms, have been done and performed.

      NOW, THEREFORE, THIS FIRST SUPPLEMENTAL INDENTURE WITNESSETH:

That in  consideration of the premises and of the acceptance and purchase of the
Floating Rate Notes by the Holders  thereof and of the  acceptance of this trust
by the Trustee, the Company covenants and agrees with the Trustee, for the equal
benefit of the Holders of the Floating Rate Notes, as follows:

                                   ARTICLE ONE

                                   Definitions

SECTION 101.  DEFINITIONS.
              -----------

      The use of the terms and  expressions  herein  is in  accordance  with the
definitions,  uses and constructions contained in the Original Indenture and the
form of the Floating Rate Notes attached hereto as Exhibit A.


                                   ARTICLE TWO

         Terms and Issuance of the Floating Rate Notes, Series A, Due

SECTION 201. Issue of Floating Rate Notes.

      A series of Senior  Notes which shall be  designated  the  "Floating  Rate
Notes,  Series A, Due 2002" shall be executed,  authenticated  and  delivered in
accordance  with the provisions of, and shall in all respects be subject to, the
terms,  conditions  and  covenants  of, the  Original  Indenture  and this First
Supplemental  Indenture  (including  the form of  Global  Security  set forth in
Exhibit A hereto).  The aggregate principal amount of the Floating Rate Notes to
be authenticated  and delivered shall be  $106,000,000,  and no further Floating
Rate Notes shall be  authenticated  and  delivered,  except as  permitted by the
provisions of the Original Indenture.

SECTION 202. Form of Floating Rate Notes; Incorporation of Terms.

      The  Floating  Rate  Notes  shall be issued  initially  in the form of one
Global  Security.  The form of the Floating Rate Notes shall be substantially in
the form of Exhibit A attached hereto. The terms of such Floating Rate Notes are
herein  incorporated  by  reference  and are  part of  this  First  Supplemental
Indenture.

SECTION 203. Depositary for Global Securities.

      The  Depositary  for any  Global  Securities  of the  series of which this
Floating Rate Note is a part shall be the  Depository  Trust Company in The City
of New York.



SECTION 204. Place of Payment.

      The Place of Payment in respect of the Floating  Rate Notes will be at the
principal  office or place of business of the Trustee or its  successor in trust
under the  Indenture,  which,  at the date  hereof,  is located  at 101  Barclay
Street, New York, NY 10286, Attention: Corporate Trust Administration.


                                  ARTICLE THREE

                                  Miscellaneous

SECTION 301. Execution as Supplemental Indenture.

      This First Supplemental Indenture is executed and shall be construed as an
indenture  supplemental  to the  Original  Indenture  and,  as  provided  in the
Original Indenture, this First Supplemental Indenture forms a part thereof.

SECTION 302. Conflict with Trust Indenture Act.

      If any  provision  hereof  limits,  qualifies  or  conflicts  with another
provision  hereof  which is required  to be included in this First  Supplemental
Indenture by any of the  provisions  of the Trust  Indenture  Act, such required
provision shall control.

SECTION 303. Effect of Headings.

      The Article and Section headings herein are for convenience only and shall
not affect the construction hereof.

SECTION 304. Successors and Assigns.

      All  covenants and  agreements  by the Company in this First  Supplemental
Indenture shall bind its successors and assigns, whether so expressed or not.

SECTION 305. Separability Clause.

      In case any  provision  in this  First  Supplemental  Indenture  or in the
Floating Rate Notes shall be invalid,  illegal or  unenforceable,  the validity,
legality and enforceability of the remaining  provisions shall not in any way be
affected or impaired thereby.

SECTION 306. Benefits of First Supplemental Indenture.

      Nothing in this  First  Supplemental  Indenture  or in the  Floating  Rate
Notes,  express or  implied,  shall give to any  Person,  other than the parties
hereto and their successors  hereunder and the Holders, any benefit or any legal
or equitable right, remedy or claim under this First Supplemental Indenture.

SECTION 307. Execution and Counterparts.

      This  First  Supplemental  Indenture  may be  executed  in any  number  of
counterparts,  each of which  shall be  deemed to be an  original,  but all such
counterparts shall together constitute but one and the same instrument.
     IN WITNESS WHEREOF,  the parties hereto have caused this First Supplemental
Indenture  to be duly  executed and  attested,  all as of the day and year first
above written.


                              PUBLIC SERVICE COMPANY OF OKLAHOMA


                              By______________________________
                                Name: A. A. Pena
                                Title: Treasurer

Attest:


-------------------------
Name: Thomas G. Berkemeyer
Title:Assistant Secretary

                              THE BANK OF NEW YORK, as Trustee


                              By______________________________
                                Name: Remo Reale
                                Title Vice President

Attest:


-------------------------
Name:
Title:

<PAGE>



STATE OF OHIO           )
                        : ss.
COUNTY OF FRANKLIN      )


      On the 21st day of November, 2000, personally appeared before me, a Notary
Public within and for said County in the State of Ohio,  A. A. Pena,  and Thomas
G. Berkemeyer,  to me known and known to me to be respectively the Treasurer and
Assistant  Secretary  of  Public  Service  Company  of  Oklahoma,   one  of  the
corporations named in and which executed the foregoing instrument, who severally
acknowledged  that they did sign said instrument as such Treasurer and Assistant
Secretary for and on behalf of said  corporation and that the same is their free
act and deed as such Treasurer and Assistant  Secretary,  respectively,  and the
free and corporate act and deed of said corporation.

In witness  whereof,  I have hereunto set my hand notarial seal this 21st day of
November, 2000.


                                        _____________________________

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


      On the 21st day of November, 2000, personally appeared before me, a Notary
Public within and for said County in the State of New York,  Remo Reale and , to
me known and known to me to be  respectively  the Vice President and of The Bank
of New York, one of the  corporations  named in and which executed the foregoing
instrument,  who severally  acknowledged  that they did sign said  instrument as
such Vice President and for and on behalf of said  corporation and that the same
is their free act and deed as such Vice  President and,  respectively,  and the
free and corporate act and deed of said corporation.

In witness  whereof,  I have hereunto set my hand notarial seal this 21st day of
November, 2000.


                                    -----------------------------
<PAGE>

                                                                       EXHIBIT A

      This  Security is a Global  Security  within the meaning of the  Indenture
hereinafter  referred  to and is  registered  in the name of a  Depositary  or a
nominee of a Depositary. This Security is exchangeable for Securities registered
in the name of a Person  other than the  Depositary  or its nominee  only in the
limited  circumstances  described  in the  Indenture,  and no  transfer  of this
Security (other than a transfer of this Security as a whole by the Depositary to
a nominee of the  Depositary or by a nominee of the Depositary to the depositary
or  another  nominee  of the  Depositary)  may be  registered  except in limited
circumstances.

      Unless this  certificate is presented by an authorized  representative  of
The Depository Trust Company, a New York corporation  ("DTC"), to Public Service
Company of  Oklahoma  or its agent for  registration  of  transfer,  exchange or
payment, and any definitive 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 in as
much as the registered owner hereof, Cede & Co., has an interest herein.

No. R-1

                      PUBLIC  SERVICE  COMPANY OF OKLAHOMA  Floating Rate Notes,
                   Series A, Due 2002

CUSIP No.
$106,000,000

      PUBLIC  SERVICE  COMPANY OF OKLAHOMA,  a  corporation  duly  organized and
existing  under the laws of the State of  Oklahoma  (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 SIX Million Dollars  ($106,000,000) on November 21,
2002 (the "Final Maturity"),  and to pay interest thereon from November 21, 2000
or from the most recent Interest Payment Date to which interest has been paid or
duly  provided  for,  quarterly in arrears on February 21, May 21, August 21 and
November 21 in each year,  commencing  February  21, 2001,  until the  principal
hereof is paid or made available for payment.

      A calculation  agent  appointed by the Company,  initially The Bank of New
York, will calculate the interest rate on this Security.  The interest rate will
be equal to LIBOR plus 0.625%.  The interest  rate in effect for the period from
November 21, 2000 to, but  excluding,  February 21, 2001,  the initial  Interest
Reset Date,  will be LIBOR, as determined on November 17, 2000, plus 0.625% (the
"Initial Interest Rate").  The calculation agent will reset the interest rate on
each Interest Payment Date (each such day an "Interest Reset Date").  The second
London  business  day  preceding  an Interest  Reset Date will be the  "Interest
Determination Date" for that Interest Reset Date. The interest rate in effect on
each day that is not an Interest Reset Date will be the interest rate determined
as of the Interest  Determination  Date pertaining to the immediately  preceding
Interest  Reset Date. The interest rate in effect on any day that is an Interest
Reset Date will be the interest rate determined as of the Interest Determination
Date  pertaining to that Interest  Reset Date,  except that the interest rate in
effect for the period from and including November 21, 2000 to the first Interest
Reset Date will be the Initial Interest Rate. The amount of interest payable for
any period will be computed on the basis of a 360-day year for the actual number
of days elapsed.  If any Interest  Payment Date (other than the Stated  Maturity
hereof or a  Redemption  Date  herefor)  would  otherwise be a day that is not a
Business Day, the payment of interest in respect of such  Interest  Payment Date
will be  postponed  to the next  succeeding  Business  Day,  except that if such
Business Day falls in the next succeeding calendar month, such interest shall be
paid on the immediately preceding Business Day. If the Stated Maturity hereof or
any Redemption  Date hereof is not a Business Day, then payment of principal and
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.  A
"Business Day" shall mean any day except a Saturday, a Sunday or a legal holiday
in The City of New York on which banking institutions are authorized or required
by law, regulation or executive order to close;  provided that the day is also a
London Business Day.  "London Business Day" means a day other than a Saturday or
Sunday that is not a day on which banking  institutions  in London,  England and
New York, New York are  authorized or obligated by law or executive  order to be
closed and a day on which dealings in deposits in U. S. dollars are  transacted,
or with respect to any future date are expected to be transacted,  in the London
interbank market.

      The  calculation  agent  will  determine  "LIBOR" in  accordance  with the
following provisions:

      (i) With respect to any  Interest  Determination  Date,  LIBOR will be the
offered rate for deposits in United States  dollars  having an index maturity of
three months  commencing on the first day of the applicable  Interest  Period in
amounts of not less than  $1,000,000  as that rate appears on Telerate Page 3750
as of 11:00 a.m., London time, on that Interest  Determination  Date. If no rate
appears,  LIBOR,  in  respect  to  that  Interest  Determination  Date,  will be
determined in accordance with the provisions described in (ii) below.

      (ii)  With  respect  to an  Interest  Determination  Date on which no rate
appears on Telerate Page 3750, as specified in (i) above, the calculation  agent
will request the principal  London offices of each of four major reference banks
in the London interbank market, as selected by the calculation agent, to provide
the calculation  agent with its offered  quotation for deposits in United States
dollars of not less than  $1,000,000 for the period of three months,  commencing
on the first day of the applicable Interest Period, to prime banks in the London
interbank  market at  approximately  11:00 a.m.,  London time,  on that Interest
Determination Date and in a principal amount that is representative for a single
transaction  in United  States  dollars in that market at that time. If at least
two quotations are provided, then LIBOR on that Interest Determination Date will
be the  arithmetic  mean of those  quotations.  If fewer than two quotations are
provided,  then LIBOR on the Interest  Determination Date will be the arithmetic
mean of the rates quoted at  approximately  11:00 a.m., in The City of New York,
on the Interest  Determination Date by three major banks in The City of New York
selected by the calculation  agent for loans in United States dollars to leading
European banks, having a three-month  maturity and in a principal amount that is
representative  for a single transaction in United States dollars in that market
at that  time;  provided,  however,  that if all of the  banks  selected  by the
calculation  agent are not providing  quotations in the manner described by this
sentence,  LIBOR determined as of that Interest Determination Date will be LIBOR
in effect on that Interest Determination Date.

      "Telerate  Page 3750"  means the  display  designated  on page 3750 on Dow
Jones  Markets  Limited (or such other page as may replace the 3750 page on that
service  or such other  service  as may be  nominated  by the  British  Bankers'
Association for the purpose of displaying  London interbank offered rates for U.
S. dollar deposits).

      "Interest  Period" means the period from and including  November 21, 2000,
to, and excluding,  the first Interest  Payment Date and thereafter,  the period
from, and including,  the immediately  preceding  Interest Payment Date to which
interest has been paid or duly provided for to, but excluding, the next Interest
Payment Date or the Maturity hereof, as the case may be.

      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 fifteenth  calendar day (whether or not a Business
Day)  immediately  preceding the 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 interest on this
Security will be made at the office or agency of the Company maintained for that
purpose in the Borough of  Manhattan,  The City of New York,  New York,  in such
coin or  currency  of the United  States of America as at the time of payment is
legal  tender for the 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.

      This Security has initially been issued in the form of a Global  Security,
and the Company has  initially  designated  The  Depository  Trust  Company (the
"Depositary",  which  term  shall  include  any  successor  depositary)  as  the
depositary for this Security. For as long as this Security or any portion hereof
is issued in such form, and notwithstanding the previous paragraph, all payments
of interest,  principal and other amounts in respect of this Security or portion
thereof shall be made to the  Depositary  or its nominee in accordance  with the
Applicable  Procedures  in the coin or currency  specified  above and as further
provided herein.

      This  Security  is one of a duly  authorized  issue of  securities  of the
Company (the "Securities"),  issued and to be issued in one or more series under
an  Indenture,  dated as of November 1, 2000, as amended and  supplemented  from
time to time (the "Indenture",  which term shall have the meaning assigned to it
in such  instrument),  between the Company and The Bank of New York,  a New York
banking  corporation,  as  Trustee  (the  "Trustee",  which  term  includes  any
successor trustee under the Indenture), as to which Indenture and all indentures
supplemental  thereto reference is hereby made for a statement of the respective
rights,  limitations of rights, duties and immunities thereunder of the Company,
the Trustee and the Holders 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
$106,000,000.  The provisions of this Security,  together with the provisions of
the Indenture,  shall govern the rights,  obligations,  duties and immunities of
the Holder, the Company and the Trustee with respect to this Security,  provided
that, if any provision of this Security necessarily conflicts with any provision
of the  Indenture,  the provision of this Security  shall be  controlling to the
fullest extent permitted under the Indenture.

      The Securities of this series are subject to redemption upon not less than
30 nor more than 60 days'  notice by mail to the Holders of such  Securities  at
their  addresses in the  Security  Register for such series at the option of the
Company,  in whole or in part, from time to time on any Interest Payment Date on
or after November 21, 2001 at a Redemption  Price equal to the principal  amount
of the  Securities  of this series to be redeemed  plus accrued  interest to the
Redemption Date.

      If  notice  has been  given as  provided  in the  Indenture  and funds for
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.

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

      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.

      Interest  payments with respect to this Security will be computed and paid
on the basis of a 360-day year for the actual number of days elapsed.

      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 a majority in principal  amount of the  Securities  at
the time  Outstanding  of all series to be  affected  (voting  as a class).  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.

      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,  premium,  if any, and
interest  on this  Security  at the  times,  place and rate,  and in the coin or
currency, herein prescribed.

      This Security shall be exchangeable for Securities registered in the names
of Persons other than the Depositary  with respect to such series or its nominee
only as provided in the Indenture. This Security shall be so exchangeable if (x)
the  Depositary  notifies the Company that it is unwilling or unable to continue
as  Depositary  for such  series or at any time  ceases to be a clearing  agency
registered as such under the Exchange Act, (y) the Company executes and delivers
to the Trustee an Officers' Certificate providing that this Security shall be so
exchangeable  or (z) there shall have  occurred  and be  continuing  an Event of
Default with respect to the  Securities of such series.  Securities so issued in
exchange for this Security shall be of the same series, having the same interest
rate,  if any,  and  maturity  and having the same  terms as this  Security,  in
authorized  denominations  and in the aggregate having the same principal amount
as this Security and  registered in such names as the Depositary for such Global
Security shall direct.

      As provided in the  Indenture and subject to certain  limitations  therein
set forth,  the transfer of a Security of the series of which this Security is a
part 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.

      For so long as this  Security is issued in the form of a Global  Security,
any  notice to be given to the Holder of this  Security  shall be deemed to have
been duly given to such Holder when given to the Depositary,  or its nominee, in
accordance with its Applicable  Procedures.  Neither the Company nor the Trustee
will have any  responsibility  with respect to those  policies and procedures or
for any notices or other  communications  among the  Depositary,  its direct and
indirect participants and the beneficial owners of this Security in global form.

      If at any time this Security is not represented by a Global Security,  any
notice to be given to the Holder of this  Security  shall be deemed to have been
duly given to such  Holder upon the mailing of such notice to the Holder at such
Holder's  address as it  appears  on the  Security  Register  maintained  by the
Company or its agent as of the close of business  preceding  the day such notice
is given.

      Neither the failure to give any notice nor any defect in any notice  given
to the Holder of this Security or any other  Security of this series will affect
the  sufficiency of any notice given to another Holder of any Securities of this
series.

      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.

      The  Indenture  provides  that the  Company,  at its  option,  (a) will be
discharged from any and all obligations in respect of the Securities (except for
certain obligations to register the transfer or exchange of Securities,  replace
stolen, lost or mutilated  Securities,  maintain paying agencies and hold moneys
for payment in trust) or (b) need not comply with certain restrictive  covenants
of the  Indenture,  in each case if the  Company  deposits,  in trust,  with the
Trustee money or U.S. Government Obligations (or Foreign Government Obligations,
if the Securities are  denominated in a foreign  currency or currencies)  which,
through the payment of interest thereon and principal thereof in accordance with
their  terms,  will  provide  money,  in an  amount  sufficient  to pay  all the
principal of, and premium,  if any, and interest,  if any, on the  Securities on
the dates such payments are due in accordance with the terms of such Securities,
and certain other conditions are satisfied.

      No  recourse  shall  be had for the  payment  of the  principal  of or the
interest  on this  Security,  or for any claim based  hereon,  or  otherwise  in
respect  hereof,  or based on or in respect of the  Indenture  or any  indenture
supplemental  thereto,  against any  incorporator,  organizer,  member,  limited
partner, stockholder,  officer or director, as such, past, present or future, of
the  Company or any  successor  Person,  whether by virtue of any  constitution,
statute or rule of law, or by the  enforcement  of any  assessment or penalty or
otherwise, all such liability being, by the acceptance hereof and as part of the
consideration for the issuance hereof, expressly waived and released.

      This Security  shall be governed by and  construed in accordance  with the
laws of the State of New York without  regard to  principles  of conflict of law
except Section 5-1401 of the New York General Obligations Law.

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

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

      IN WITNESS  WHEREOF,  Public  Service  Company of Oklahoma has caused this
instrument to be duly executed under its corporate seal.

                              PUBLIC SERVICE COMPANY OF OKLAHOMA


                              By______________________________________
                                Name: A. A. Pena
                                Title: Treasurer


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

Dated: November 21, 2000                  THE BANK OF NEW YORK


                                    By
                                       ---------------------------------
                                          Authorized Signatory


      FOR VALUE  RECEIVED,  the  undersigned  hereby  sell(s),  assign(s)  and
transfer(s) unto

(PLEASE INSERT SOCIAL SECURITY OR OTHER
   IDENTIFYING NUMBER OF ASSIGNEE)


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(PLEASE PRINT OR TYPE NAME AND ADDRESS, INCLUDING ZIP CODE, OF
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ASSIGNEE) the within Note and all rights thereunder, hereby
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irrevocably constituting and appointing such person attorney to
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transfer such Note on the books of the Issuer, with full
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power of substitution in the premises.



Dated:________________________            _________________________



NOTICE:     The signature to this  assignment must correspond with the name as
            written  upon the  face of the  within  Note in every  particular,
            without  alteration  or  enlargement  or any change  whatever  and
            NOTICE:   Signature(s)   must  be   guaranteed   by  a   financial
            institution  that is a member of the  Securities  Transfer  Agents
            Medallion Program ("STAMP"),  the Stock Exchange Medallion Program
            ("SEMP") or the New York Stock Exchange,  Inc. Medallion Signature
            Program ("MSP").