EXHIBIT 4(d)








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                       PUBLIC SERVICE COMPANY OF OKLAHOMA


                                       and


                              THE BANK OF NEW YORK,
                                   AS TRUSTEE


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


                          THIRD SUPPLEMENTAL INDENTURE

                         Dated as of September 15, 2003


                          Supplemental to the Indenture
                          dated as of November 1, 2000


                     4.85% Senior Notes, Series C, due 2010




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<PAGE>




         THIRD SUPPLEMENTAL INDENTURE, dated as of September 15, 2003, 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 $150,000,000 to be designated the "4.85% Senior
Notes, Series C, due 2010" (the "4.85% Senior Notes"), and all action on the
part of the Company necessary to authorize the issuance of the 4.85% Senior
Notes under the Original Indenture and this Third Supplemental Indenture has
been duly taken.

         All acts and things necessary to make the 4.85% Senior Notes, when
executed by the Company and completed, authenticated and delivered by the
Trustee as provided in the Original Indenture and this Third 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 THIRD SUPPLEMENTAL INDENTURE WITNESSETH:

         That in consideration of the premises and of the acceptance and
purchase of the 4.85% Senior 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 4.85% Senior Notes, as follows:

                                   ARTICLE ONE
                                   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 Global Security attached hereto as Exhibit A.

                                   ARTICLE TWO
                  Terms and Issuance of the 4.85% Senior Notes

SECTION 201. Issue of 4.85% Senior Notes

         A series of Senior Notes which shall be designated the "4.85% Senior
Notes, Series C, due 2010" shall be executed, authenticated and delivered from
time to time 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 Third Supplemental Indenture (including the form of Global Security set
forth in Exhibit A hereto). The aggregate principal amount of the 4.85% Senior
Notes, which may be authenticated and delivered under this Third Supplemental
Indenture shall not, except as permitted by the provisions of the Original
Indenture, exceed $150,000,000.

SECTION 202. Form of 4.85% Senior Notes, Incorporation of Terms

         The 4.85% Senior Notes shall be substantially in the form of the Global
Security attached hereto as Exhibit A. The terms of such 4.85% Senior Notes are
herein incorporated by reference and are part of this Third Supplemental
Indenture.

SECTION 203. Depositary for Global Securities

         The Depositary for any Global Securities of the series of which this
4.85% Senior Note is a part shall be The Depository Trust Company in The City of
New York.

SECTION 204. Restrictions on Liens

         The covenant contained in Section 1007 of the Original Indenture shall
not be applicable to the 4.85% Senior Notes.

         So long as any of the 4.85% Senior Notes are outstanding, the Company
will not create or suffer to be created or to exist any additional mortgage,
pledge, security interest, or other lien (collectively "Liens") on any of its
utility properties or tangible assets now owned or hereafter acquired to secure
any indebtedness for borrowed money ("Secured Debt"), without providing that the
4.85% Senior Notes will be similarly secured. This restriction does not apply to
the Company's subsidiaries, nor will it prevent any of them from creating or
permitting to exist Liens on their property or assets to secure any Secured
Debt. Further, this restriction on Secured Debt does not apply to the Company's
existing first mortgage bonds that have previously been issued under its
Mortgage and Deed of Trust, dated July 1, 1945, between the Company and Liberty
Bank and Trust Company of Tulsa, National Association, as successor to The first
National Bank and Trust Company of Tulsa, as Trustee or any indenture
supplemental thereto; provided that this restriction will apply to future
issuances thereunder (other than issuances of refunding first mortgage bonds).
In addition, this restriction does not prevent the creation or existence of:

         (a) Liens on property existing at the time of acquisition or
construction of such property (or created within one year after completion of
such acquisition or construction), whether by purchase, merger, construction or
otherwise, or to secure the payment of all or any part of the purchase price or
construction cost thereof, including the extension of any Liens to repairs,
renewals, replacements, substitutions, betterments, additions, extensions and
improvements then or thereafter made on the property subject thereto;

         (b) Financing of the Company's accounts receivable for electric
service;

         (c) Any extensions, renewals or replacements (or successive extensions,
renewals or replacements), in whole or in part, of liens permitted by the
foregoing clauses; and

         (d) The pledge of any bonds or other securities at any time issued
under any of the Secured Debt permitted by the above clauses.

         In addition to the permitted issuances above, Secured Debt not
otherwise so permitted may be issued in an amount that does not exceed 15% of
Net Tangible Assets as defined below.

         "Net Tangible Assets" means the total of all assets (including
revaluations thereof as a result of commercial appraisals, price level
restatement or otherwise) appearing on the Company's balance sheet, net of
applicable reserves and deductions, but excluding goodwill, trade names,
trademarks, patents, unamortized debt discount and all other like intangible
assets (which term shall not be construed to include such revaluations), less
the aggregate of the Company's current liabilities appearing on such balance
sheet. For purposes of this definition, the Company's balance sheet does not
include assets and liabilities of its subsidiaries.

         This restriction also does not apply to or prevent the creation or
existence of leases made, or existing on property acquired, in the ordinary
course of business.

SECTION 205. Place of Payment

         The Place of Payment in respect of the 4.85% Senior 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 10281, Attention: Corporate Trust Trustee.

SECTION 206. Sinking Funds.

         Article Twelve of the Indenture shall not apply to the Series B Notes.

SECTION 207. Redemption

         The 4.85% Senior Notes shall be redeemable at the option of the
Company, in whole at any time or in part from time to time, upon not less than
thirty but not more than sixty days' previous notice given by mail to the
registered owners of the 4.85% Senior Notes at a redemption price equal to the
greater of (i) 100% of the principal amount of the 4.85% Senior Notes being
redeemed and (ii) the sum of the present values of the remaining scheduled
payments of principal and interest on the 4.85% Senior Notes being redeemed
(excluding the portion of any such interest accrued to the date of redemption)
discounted (for purposes of determining present value) to the redemption date on
a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months)
at the Treasury Rate (as defined below) plus 20 basis points, plus, in each
case, accrued interest thereon to the date of redemption.

                  "Comparable Treasury Issue" means the United States Treasury
                  security selected by an Independent Investment Banker as
                  having a maturity comparable to the remaining term of the
                  4.85% Senior Notes 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.

                  "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 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 third Business Day, the
                  Reference Treasury Dealer Quotation for such redemption date.

                  "Independent Investment Banker" means one of the Reference
                  Treasury Dealers appointed by the Company and reasonably
                  acceptable to the Trustee.

                  "Reference Treasury Dealer" means a primary U.S. government
                  securities dealer in New York City selected by the Company and
                  reasonably acceptable to the Trustee.

                  "Reference Treasury Dealer Quotation" means, with respect to
                  the 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 or
                  before 5:00 p.m., New York City time, on the third Business
                  Day preceding such redemption date.

                  "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, assuming 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.


                                  ARTICLE THREE
                                  Miscellaneous

SECTION 301. Execution as Supplemental Indenture

         This Third Supplemental Indenture is executed and shall be construed as
an indenture supplemental to the Original Indenture and, as provided in the
Original Indenture, this Third 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 Third 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 Third Supplemental
Indenture shall bind its successors and assigns, whether so expressed or not.

SECTION 305. Separability Clause

         In case any provision in this Third Supplemental Indenture or in the
4.85% Senior 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 Third Supplemental Indenture

         Nothing in this Third Supplemental Indenture or in the 4.85% Senior
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 Third Supplemental Indenture.

SECTION 307. Execution and Counterparts

         This Third 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 Third
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.


                                            PUBLIC SERVICE COMPANY OF OKLAHOMA


                                            By: /s/ Wendy G. Hargus
                                                Assistant Treasurer

Attest:


/s/ Thomas G. Berkemeyer
Assistant Secretary

                                            THE BANK OF NEW YORK,
                                            as Trustee


                                            By  /s/ Joseph A. Lloret
                                                Authorized Signatory



Attest:


/s/  Timothy J. Shea
Name:  Timothy J. Shea
Title: Assistant Treasurer



<PAGE>


STATE OF OHIO      )
                   : ss.:
COUNTY OF FRANKLIN )


         On the 15th day of September, 2003, before me personally came Wendy G.
Hargus, to me known, who, being by me duly sworn, did depose and say that she is
an Assistant Treasurer of Public Service Company of Oklahoma, one of the
corporations described in and which executed the foregoing instrument; that she
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 she signed her name thereto by like
authority.


                          /s/ Mary M. Soltesz
                          My Commission expires 7-13-04


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


         On the 15th day of September, 2003, before me personally came Joseph A.
Lloret, to me known, who, being by me duly sworn, did depose and say that he is
an Assistant Treasurer of The Bank of New York, a New York banking corporation,
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.


                           /s/ Robert Hirsch
                            Commission expires 7-1-06




<PAGE>

                                                                      EXHIBIT A

                        [Form of Face of Global Security]

         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
                     4.85% Senior Notes, Series C, due 2010

CUSIP No. 744533BE9                                               $150,000,000

         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 FIFTY Million Dollars ($150,000,000) on September
15, 2010 (the "Final Maturity"), and to pay interest thereon from September 15,
2003 or from the most recent Interest Payment Date to which interest has been
paid or duly provided for, semi-annually on March 15 and September 15 each year,
commencing March 15, 2004, at the interest rate per annum specified above, until
the principal amount shall have been paid or duly provided for. Interest shall
be computed on the basis of a 360-day year of twelve 30-day months.

         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 February 28 or August 31 (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
$150,000,000; provided, however, the aggregate principal amount hereof can be
increased, without the consent of the Holder, as permitted by the provisions of
the Original Indenture. 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 at a Redemption Price equal to
the greater of (i) 100% of the principal amount of the Notes being redeemed and
(ii) the sum of the present values of the remaining scheduled payments of
principal and interest on the Notes being redeemed (excluding the portion of any
such interest accrued to the date of redemption) discounted (for purposes of
determining present value) to the redemption date on a semi-annual basis
(assuming a 360-day year consisting of twelve 30-day months) at the Treasury
Rate (as defined below) plus 20 basis points, plus, in each case, accrued
interest thereon to the date of redemption.

         "Comparable Treasury Issue" means the United States Treasury security
         selected by an Independent Investment Banker as having a maturity
         comparable to the remaining term of the Notes 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.

         "Comparable Treasury Price" means, with respect to any redemption date,
         (1) 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 (2) if such release
         (or any successor release) is not published or does not contain such
         prices on such third Business Day, the Reference Treasury Dealer
         Quotation for such redemption date.

         "Independent Investment Banker" means one of the Reference Treasury
         Dealers appointed by the Company and reasonably acceptable to the
         Trustee.

         "Reference Treasury Dealer" means a primary U. S. government securities
         dealer in New York City selected by the Company and reasonably
         acceptable to the Trustee.

         "Reference Treasury Dealer Quotation" means, with respect to the
         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 or before 5:00 p.m., New York City time,
         on the third Business Day preceding such redemption date.

         "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, assuming 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.

         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 of twelve 30-day months 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 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_________________________________
                                                     Assistant Treasurer

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

Dated: September 15, 2003                   THE BANK OF NEW YORK


                                               --------------------------------
                                                     Authorized Signatory



<PAGE>


     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").