SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                    FORM 8-K

                                 CURRENT REPORT

                     PURSUANT TO SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                        Date of Report: November 21, 2002
                        (Date of earliest event reported)

Commission          Registrant; State of Incorporation;         I.R.S. Employer
File Number           Address; and Telephone Number           Identification No.

  0-343             PUBLIC SERVICE COMPANY OF OKLAHOMA           73-0410895
                    (An Oklahoma Corporation)
                    1 Riverside Plaza
                    Columbus, Ohio 43215
                    Telephone (614) 223-1000

Item 5. Other Events.

         On November 21, 2002, Public Service Company of Oklahoma (the
"Company") entered into an Underwriting Agreement with Merrill Lynch, Pierce,
Fenner & Smith Incorporated, Salomon Smith Barney Inc., and UBS Warburg LLC, as
representatives of the underwriters named therein, relating to the offering and
sale by the Company of $200,000,000 of its 6% Senior Notes, Series B, due 2032
(the "Notes").

         The consolidated financial statements of Ambac Assurance Corporation
and subsidiaries as of December 31, 2001 and December 31, 2000, and for each of
the years in the three-year period ended December 31, 2001, prepared in
accordance with accounting principles generally accepted in the United States of
America, included in the Annual Report on Form 10-K of Ambac Financial Group,
Inc. (filed with the Securities and Exchange Commission, or "SEC", on March 26,
2002, File Number 1-10777), the unaudited consolidated interim financial
statements of Ambac Assurance Corporation and subsidiaries as of March 31, 2002
and for the periods ended March 31, 2002 and March 31, 2001 included in the
Quarterly Report on Form 10-Q of Ambac Financial Group, Inc. (filed with the SEC
on May 13, 2002); as of June 30, 2002 and for the periods ended June 30, 2002
and June 30, 2001 included in the Quarterly Report on Form 10-Q of Ambac
Financial Group, Inc. (filed with the SEC on August 14, 2002); and as of
September 30, 2002 and for the periods ended September 30, 2002 and September
30, 2001 included in the Quarterly Report on Form 10-Q of Ambac Financial Group,
Inc. (filed with the SEC on November 14, 2002); and Current Reports on Form 8-K
of Ambac Financial Group, Inc. filed with the SEC on January 25, 2002, April 18,
2002, July 19, 2002, August 14, 2002, October 17, 2002 and November 20, 2002, as
such current reports related to Ambac Assurance Corporation, are hereby
incorporated by reference into (i) this Current Report on Form 8-K, (ii) the
Registration Statement of the Company on Form S-3 (File No. 333-100623)(the
"Registration Statement"), and (iii) the Prospectus Supplement of the Company
dated November 21, 2002 and relating to the offering of the Notes pursuant to
the Registration Statement..

Item 7. Financial Statements and Exhibits.

     (c) Exhibits.

     1(a) Underwriting  Agreement,  dated November 21, 2002, between the Company
          and Merrill Lynch, Pierce, Fenner & Smith Incorporated,  Salomon Smith
          Barney Inc.,  and UBS Warburg LLC, as  representatives  of the several
          underwriters  named in Exhibit 1 thereto,  in connection with the sale
          of the Notes.

     4(a) Supplemental  Indenture,  dated  November 21, 2002,  establishing  the
          terms of the Notes.

     4(b) Form of the Notes (included in Exhibit 4(a) hereto).

     5(a) Opinion of Simpson  Thacher & Bartlett  regarding  the legality of the
          Notes.

     23   Consent of KPMG LLP.

                                    SIGNATURE

         Pursuant to the requirements of the Securities Exchange Act of 1934,
the Registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.

                                            PUBLIC SERVICE COMPANY OF OKLAHOMA



                                            By:   /s/ Thomas G. Berkemeyer
                                                Name: Thomas G. Berkemeyer
                                                Title: Assistant Secretary

November 26, 2002


                                                                   EXHIBIT 1(a)

                       PUBLIC SERVICE COMPANY OF OKLAHOMA

                             Underwriting Agreement

                             Dated November 21, 2002

     AGREEMENT made between PUBLIC  SERVICE  COMPANY OF OKLAHOMA,  a corporation
organized and existing  under the laws of the State of Oklahoma  (the  Company),
and the several persons,  firms and  corporations  (the  Underwriters)  named in
Exhibit 1 hereto.

                                   WITNESSETH:

     WHEREAS,  the  Company  proposes to issue and sell  $200,000,000  principal
amount of its 6% Senior  Notes,  Series  B, due 2032  (the  Senior  Notes) to be
issued  pursuant to the  Indenture  dated as of  November  1, 2000,  between the
Company  and The Bank of New York,  as  trustee  (the  Trustee),  as  heretofore
supplemented  and amended and as to be further  supplemented  and amended  (said
Indenture as so supplemented being hereafter referred to as the Indenture); and

     WHEREAS,  in connection with the issuance of the Senior Notes,  the payment
of principal of (at stated maturity), and interest on, the Senior Notes shall be
unconditionally and irrevocably  guaranteed by Ambac Assurance  Corporation (the
Insurer)  pursuant  to a financial  guaranty  insurance  policy  (the  Insurance
Policy); and

     WHEREAS,   the  Underwriters  have  designated  the  persons  signing  this
Agreement  (collectively the Representative) to execute this Agreement on behalf
of the respective Underwriters and to act for the respective Underwriters in the
manner provided in this Agreement; and

     WHEREAS,  the  Company  has  prepared  and filed,  in  accordance  with the
provisions of the  Securities  Act of 1933 (the Act),  with the  Securities  and
Exchange  Commission  (the  Commission),  a  registration  statement  (File  No.
333-100623) and a prospectus  relating to $400,000,000  principal  amount of its
Unsecured Notes and such registration statement has become effective; and

     WHEREAS, such registration  statement,  including the financial statements,
the documents  incorporated  or deemed  incorporated  therein by reference,  the
exhibits  thereto,  being  herein  called the  Registration  Statement,  and the
prospectus,  including the documents incorporated or deemed incorporated therein
by reference,  constituting a part of such Registration  Statement, as it may be
last amended or supplemented  prior to the effectiveness of this Agreement,  but
excluding any amendment or supplement  relating solely to securities  other than
the  Senior  Notes,  being  herein  called the Basic  Prospectus,  and the Basic
Prospectus,  as supplemented by a preliminary  prospectus supplement and a final
prospectus  supplement  (the  Prospectus   Supplement)  to  include  information
relating to the Senior Notes, including the names of the Underwriters, the price
and terms of the offering,  the interest  rate,  maturity date and certain other
information  relating  to the  Senior  Notes,  which  will  be  filed  with  the
Commission  pursuant  to Rule  424(b)  of the  Commission's  General  Rules  and
Regulations under the Act (the Rules), including all documents then incorporated
or deemed to have been  incorporated  therein by reference,  being herein called
the Prospectus.  NOW, THEREFORE, in consideration of the premises and the mutual
covenants herein contained, it is agreed between the parties as follows:

     1. Purchase and Sale: Upon the basis of the warranties and  representations
and on the terms and  subject to the  conditions  herein set forth,  the Company
agrees  to sell to the  respective  Underwriters  named  in  Exhibit  1  hereto,
severally and not jointly,  and the respective  Underwriters,  severally and not
jointly, agree to purchase from the Company, the respective principal amounts of
the  Senior  Notes set  opposite  their  names in  Exhibit  1  hereto,  together
aggregating all of the Senior Notes, at a price equal to 96.85% of the principal
amount thereof.

     2. Payment and Delivery:  Payment for the Senior Notes shall be made to the
Company in  immediately  available  funds or in such other manner as the Company
and the Representative  shall mutually agree upon in writing,  upon the delivery
of the Senior Notes to the  Representative  for the  respective  accounts of the
Underwriters  against receipt therefor signed by the Representative on behalf of
itself  and for the other  Underwriters.  Such  delivery  shall be made at 10:00
A.M.,  New York Time,  on November 26, 2002 (or on such later  business day, not
more than five business days  subsequent to such day, as may be mutually  agreed
upon by the Company and the  Underwriters),  unless postponed in accordance with
the provisions of Section 8 hereof, at the office of Simpson Thacher & Bartlett,
425 Lexington  Avenue,  New York, New York 10017,  or at such other place as the
Company and the  Representative  shall  mutually  agree in writing.  The time at
which payment and delivery are to be made is herein called the Time of Purchase.

     The  delivery of the Senior Notes shall be made in fully  registered  form,
registered  in the name of CEDE & CO.,  to the offices of The  Depository  Trust
Company in New York, New York and the Underwriters shall accept such delivery.

     3. Conditions of Underwriters' Obligations:  The several obligations of the
Underwriters  hereunder  are  subject  to the  accuracy  of the  warranties  and
representations on the part of the Company on the date hereof and at the Time of
Purchase and to the following other conditions:

     (a)  That all legal  proceedings  to be taken and all legal  opinions to be
          rendered in connection with the issue and sale of the Senior Notes and
          the issuance of the Insurance Policy shall be satisfactory in form and
          substance to Dewey Ballantine LLP, counsel to the Underwriters.

     (b)  That, at the Time of Purchase,  the Representative  shall be furnished
          with the  following  opinions,  dated the day of the Time of Purchase,
          with  conformed  copies or signed  counterparts  thereof for the other
          Underwriters,  with such changes  therein as may be agreed upon by the
          Company and the  Representative  with the approval of Dewey Ballantine
          LLP, counsel to the Underwriters:

          (1)  Opinion  of Simpson  Thacher &  Bartlett  and either of Thomas G.
               Berkemeyer, Esq. or David C. House, Esq., counsel to the Company,
               substantially in the forms heretofore  previously provided to the
               Underwriters;

          (2)  Opinion of Dewey  Ballantine  LLP,  counsel to the  Underwriters,
               substantially in the form heretofore  previously  provided to the
               Underwriters;

          (3)  Opinion of counsel to the Insurer.

     (c)  That the  Representative  shall have received a letter from Deloitte &
          Touche LLP in form and substance  satisfactory to the  Representative,
          dated as of the day of the Time of Purchase,  (i) confirming that they
          are independent certified public accountants within the meaning of the
          Act  and  the  applicable  published  rules  and  regulations  of  the
          Commission  thereunder,   (ii)  stating  that  in  their  opinion  the
          financial  statements  audited by them and included or incorporated by
          reference  in the  Registration  Statement  complied as to form in all
          material respects with the then applicable accounting  requirements of
          the   Commission,   including  the  applicable   published  rules  and
          regulations of the Commission and (iii) covering as of a date not more
          than five  business days prior to the day of the Time of Purchase such
          other matters as the Representative reasonably requests.

     (d)  That no amendment to the Registration Statement and that no prospectus
          or prospectus  supplement of the Company (other than the prospectus or
          amendments,  prospectuses or prospectus supplements relating solely to
          securities  other than the Senior Notes)  relating to the Senior Notes
          and no document which would be deemed  incorporated  in the Prospectus
          by reference filed subsequent to the date hereof and prior to the Time
          of Purchase shall contain material information substantially different
          from  that   contained  in  the   Registration   Statement   which  is
          unsatisfactory in substance to the Representative or unsatisfactory in
          form to Dewey Ballantine LLP, counsel to the Underwriters.

     (e)  That, at the Time of Purchase,  an  appropriate  order of the Oklahoma
          State  Corporation  Commission,  necessary  to permit  the sale of the
          Senior Notes to the Underwriters,  shall be in effect; and that, prior
          to  the  Time  of  Purchase,   no  stop  order  with  respect  to  the
          effectiveness  of the  Registration  Statement  shall have been issued
          under the Act by the Commission or proceedings therefor initiated.

     (f)  That,  from the date hereof to the Time of  Purchase,  there shall not
          have been any material  adverse change in the business,  properties or
          financial  condition  of  the  Company  from  that  set  forth  in the
          Prospectus  (other than changes  referred to in or contemplated by the
          Prospectus), and that the Company shall, at the Time of Purchase, have
          delivered to the  Representative a certificate of an executive officer
          of the  Company  to the  effect  that,  to the best of his  knowledge,
          information and belief, there has been no such change.

     (g)  That,  at the Time of  Purchase,  the Trustee  shall have  received an
          executed copy of the Insurance Policy.

     (h)  That, at the Time of Purchase,  the Representative shall have received
          evidence that the Senior Notes have been rated "Aaa" (stable  outlook)
          by Moody's  Investors  Service,  Inc.  and "AAA"  (stable  outlook) by
          Standard & Poor's Ratings Services.

     (i)  That the Company shall have  performed such of its  obligations  under
          this  Agreement  as are to be  performed  at or  before  the  Time  of
          Purchase by the terms hereof.

     4.  Certain  Covenants  of the  Company:  In further  consideration  of the
agreements  of the  Underwriters  herein  contained,  the Company  covenants  as
follows:

     (a)  As soon as practicable, and in any event within the time prescribed by
          Rule 424 under the Act, to file the Prospectus with the Commission; as
          soon as the Company is advised thereof,  to advise the  Representative
          and  confirm  the  advice  in  writing  of  any  request  made  by the
          Commission for amendments to the Registration  Statement or Prospectus
          or for additional  information with respect thereto or of the entry of
          a  stop  order  suspending  the   effectiveness  of  the  Registration
          Statement or of the initiation or threat of any  proceedings  for that
          purpose and, if such a stop order should be entered by the Commission,
          to make  every  reasonable  effort to obtain  the  prompt  lifting  or
          removal thereof.

     (b)  To deliver to the Underwriters, without charge, as soon as practicable
          (and in any event  within 24 hours  after the date  hereof),  and from
          time to time thereafter during such period of time (not exceeding nine
          months) after the date hereof as they are required by law to deliver a
          prospectus,  as many  copies of the  Prospectus  (as  supplemented  or
          amended if the Company shall have made any  supplements  or amendments
          thereto,  other than  supplements  or  amendments  relating  solely to
          securities  other than the  Senior  Notes) as the  Representative  may
          reasonably request; and in case any Underwriter is required to deliver
          a  prospectus  after  the  expiration  of nine  months  after the date
          hereof, to furnish to any Underwriter, upon request, at the expense of
          such Underwriter,  a reasonable quantity of a supplemental  prospectus
          or of supplements to the Prospectus complying with Section 10(a)(3) of
          the Act.

     (c)  To furnish to the Representative a copy, certified by the Secretary or
          an Assistant Secretary of the Company,  of the Registration  Statement
          as initially  filed with the Commission and of all amendments  thereto
          (exclusive  of exhibits),  other than  amendments  relating  solely to
          securities  other than the Senior Notes and, upon request,  to furnish
          to the  Representative  sufficient plain copies thereof  (exclusive of
          exhibits) for distribution to the other Underwriters.

     (d)  For such period of time (not  exceeding  nine  months)  after the date
          hereof as they are  required  by law to deliver a  prospectus,  if any
          event  shall have  occurred  as a result of which it is  necessary  to
          amend or supplement  the  Prospectus  in order to make the  statements
          therein,  in the light of the  circumstances  when the  Prospectus  is
          delivered  to a  purchaser,  not  contain  any untrue  statement  of a
          material  fact or not omit to state any material  fact  required to be
          stated  therein or necessary in order to make the  statements  therein
          not misleading,  forthwith to prepare and furnish, at its own expense,
          to the  Underwriters  and to dealers  (whose names and  addresses  are
          furnished  to the  Company by the  Representative)  to whom  principal
          amounts of the Senior  Notes may have been sold by the  Representative
          for the accounts of the Underwriters  and, upon request,  to any other
          dealers  making  such  request,  copies  of  such  amendments  to  the
          Prospectus or supplements to the Prospectus.

     (e)  As soon as practicable,  the Company will make generally  available to
          its security holders and to the Underwriters an earnings  statement or
          statement of the Company and its  subsidiaries  which will satisfy the
          provisions of Section 11(a) of the Act and Rule 158 under the Act.

     (f)  To use its best efforts to qualify the Senior Notes for offer and sale
          under the securities or "blue sky" laws of such  jurisdictions  as the
          Representative  may designate  within six months after the date hereof
          and itself to pay, or to reimburse the  Underwriters and their counsel
          for, reasonable filing fees and expenses in connection therewith in an
          amount not exceeding  $3,500 in the aggregate  (including  filing fees
          and expenses paid and incurred  prior to the  effective  date hereof),
          provided,  however,  that the Company shall not be required to qualify
          as a foreign corporation or to file a consent to service of process or
          to file annual reports or to comply with any other requirements deemed
          by the Company to be unduly burdensome.

     (g)  To pay all  expenses,  fees and taxes  (other than  transfer  taxes on
          resales  of the  Senior  Notes  by  the  respective  Underwriters)  in
          connection  with the issuance and delivery of the Senior Notes and the
          issuance of the Insurance  Policy,  provided that the Company shall be
          required to pay the fees and disbursements  (other than  disbursements
          referred to in paragraph  (f) of this  Section 4) of Dewey  Ballantine
          LLP,  counsel  to the  Underwriters,  only in the events  provided  in
          paragraph  (h) of this Section 4 and  paragraph  (a) of Section 7, the
          Underwriters hereby agreeing to pay such fees and disbursements in any
          other event.

     (h)  If the Underwriters shall not take up and pay for the Senior Notes due
          to the  failure of the  Company to comply  with any of the  conditions
          specified  in  Section  3  hereof,  or,  if this  Agreement  shall  be
          terminated in accordance with the provisions of Section 8 or 9 hereof,
          to pay the fees and  disbursements of Dewey Ballantine LLP, counsel to
          the Underwriters,  and, if the Underwriters  shall not take up and pay
          for the Senior  Notes due to the failure of the Company to comply with
          any of the conditions  specified in Section 3 hereof, to reimburse the
          Underwriters  for  their  reasonable  out-of-pocket  expenses,  in  an
          aggregate  amount  not  exceeding  a total  of  $10,000,  incurred  in
          connection with the financing contemplated by this Agreement.

     (i)  The Company will timely file any certificate required by Rule 52 under
          the Public Utility  Holding Company Act of 1935 in connection with the
          sale of the Senior Notes.

     (j)  During the period from the date hereof and continuing to and including
          the  earlier  of (i) the date which is after the Time of  Purchase  on
          which the  distribution  of the Senior Notes ceases,  as determined by
          the Representative in its sole discretion,  and (ii) the date which is
          30 days after the Time of Purchase,  the Company  agrees not to offer,
          sell, contract to sell or otherwise dispose of any Senior Notes of the
          Company or any substantially  similar securities of the Company (other
          than the Company's Senior Notes,  Series C) without the consent of the
          Representative.

     (k)  The Company  will use its best  efforts to list,  subject to notice of
          issuance, the Senior Notes on the New York Stock Exchange.

     5. Warranties of the Company: The Company represents and warrants to you as
set forth below:

     (a)  the  Registration  Statement on its effective  date  complied,  or was
          deemed to comply,  with the  applicable  provisions of the Act and the
          rules and regulations of the Commission and the Registration Statement
          at its  effective  date did not, and at the Time of Purchase will not,
          contain  any untrue  statement  of a material  fact or omit to state a
          material fact  required to be stated  therein or necessary to make the
          statements  therein not  misleading,  and the Basic  Prospectus on the
          date  of this  Agreement  and  the  Prospectus  when  first  filed  in
          accordance with Rule 424(b) complies,  and at the Time of Purchase the
          Prospectus will comply, with the applicable  provisions of the Act and
          the  Trust  Indenture  Act of 1939,  as  amended,  and the  rules  and
          regulations  of the  Commission,  the Basic  Prospectus on the date of
          this Agreement and the Prospectus  when first filed in accordance with
          Rule 424(b)  under the Act do not, and the  Prospectus  at the Time of
          Purchase will not,  contain any untrue statement of a material fact or
          omit to  state a  material  fact  required  to be  stated  therein  or
          necessary  to  make  the  statements  therein,  in  the  light  of the
          circumstances under which they were made, not misleading,  except that
          the Company makes no warranty or  representation  to the  Underwriters
          with respect to any statements or omissions  made in the  Registration
          Statement, the Basic Prospectus or the Prospectus in reliance upon and
          in conformity with information furnished in writing to the Company by,
          or through the Representative on behalf of, any Underwriter  expressly
          for  use  in the  Registration  Statement,  the  Basic  Prospectus  or
          Prospectus, or to any statements in or omissions from that part of the
          Registration   Statement  that  shall   constitute  the  Statement  of
          Eligibility  under the Trust  Indenture  Act of 1939 of any  indenture
          trustee under an indenture of the Company.

     (b)  As of the  Time  of  Purchase,  the  Indenture  will  have  been  duly
          authorized by the Company and duly qualified under the Trust Indenture
          Act of 1939,  as amended,  and,  when  executed  and  delivered by the
          Trustee and the Company,  will  constitute a legal,  valid and binding
          instrument  enforceable  against  the Company in  accordance  with its
          terms and such Senior Notes will have been duly authorized,  executed,
          authenticated  and,  when  paid for by the  purchasers  thereof,  will
          constitute  legal,  valid  and  binding  obligations  of  the  Company
          entitled   to  the   benefits   of  the   Indenture,   except  as  the
          enforceability  thereof may be limited by bankruptcy,  insolvency,  or
          other similar laws affecting the  enforcement of creditors'  rights in
          general,  and except as the  availability  of the  remedy of  specific
          performance is subject to general  principles of equity (regardless of
          whether  such remedy is sought in a  proceeding  in equity or at law),
          and by an implied covenant of good faith and fair dealing.

     (c)  The documents  incorporated by reference in the Registration Statement
          or Prospectus,  when they were filed with the Commission,  complied in
          all material  respects with the applicable  provisions of the 1934 Act
          and the rules and regulations of the Commission thereunder,  and as of
          such time of filing,  when read together with the Prospectus,  none of
          such  documents  contained an untrue  statement of a material  fact or
          omitted  to state a material  fact  required  to be stated  therein or
          necessary  to  make  the  statements  therein,  in  the  light  of the
          circumstances under which they were made, not misleading.

     (d)  Since the  respective  dates as of which  information  is given in the
          Registration  Statement  and  the  Prospectus,   except  as  otherwise
          referred  to or  contemplated  therein,  there  has  been no  material
          adverse change in the business,  properties or financial  condition of
          the Company.

     (e)  This Agreement has been duly authorized, executed and delivered by the
          Company.

     (f)  The  consummation  by the  Company  of the  transactions  contemplated
          herein is not in violation  of its charter or bylaws,  will not result
          in the violation of any applicable  law,  statute,  rule,  regulation,
          judgment,  order,  writ  or  decree  of  any  government,   government
          instrumentality  or court having  jurisdiction over the Company or its
          properties,  and will not conflict  with, or result in a breach of any
          of the terms or  provisions  of, or  constitute  a default  under,  or
          result  in  the  creation  or  imposition  of  any  lien,   charge  or
          encumbrance  upon any  property  or  assets of the  Company  under any
          contract,  indenture,  mortgage, loan agreement,  note, lease or other
          agreement or instrument to which the Company is a party or by which it
          may be bound or to which any of its properties may be subject  (except
          for conflicts,  breaches or defaults which would not,  individually or
          in the aggregate,  be materially  adverse to the Company or materially
          adverse to the transactions contemplated by this Agreement.)

     (g)  No  authorization,   approval,  consent  or  order  of  any  court  or
          governmental  authority or agency is necessary in connection  with the
          issuance  and  sale  by  the  Company  of  the  Senior  Notes  or  the
          transactions by the Company contemplated in this Agreement, except (A)
          such  as may  be  required  under  the  1933  Act  or  the  rules  and
          regulations  thereunder;  (B) such as may be required under the Public
          Utility Holding Company Act of 1935, as amended; (C) the qualification
          of the Indenture  under the 1939 Act; (D) the approval of the Oklahoma
          State  Corporation  Commission;  and  (E)  such  consents,  approvals,
          authorizations,  registrations  or  qualifications  as may be required
          under state securities or Blue Sky laws.

     (h)  The  consolidated   financial   statements  of  the  Company  and  its
          consolidated subsidiaries together with the notes thereto, included or
          incorporated  by  reference  in  the  Prospectus  present  fairly  the
          financial  position  of the  Company  at the dates or for the  periods
          indicated;  said consolidated  financial statements have been prepared
          in  accordance  with  United  States  generally  accepted   accounting
          principles applied, apart from reclassifications disclosed therein, on
          a consistent basis throughout the periods  involved;  and the selected
          consolidated  financial  information  of the  Company  included in the
          Prospectus  present fairly the information shown therein and have been
          compiled,  apart from reclassifications  disclosed therein, on a basis
          consistent  with  that  of the  audited  financial  statements  of the
          Company included or incorporated by reference in the Prospectus.

     (i)  There  is  no  pending  action,  suit,  investigation,  litigation  or
          proceeding,  including,  without limitation, any environmental action,
          affecting  the  Company  before  any  court,  governmental  agency  or
          arbitration  that is  reasonably  likely  to have a  material  adverse
          effect on the business, properties,  financial condition or results of
          operations of the Company, except as disclosed in the Prospectus

     The Company's covenants,  warranties and representations  contained in this
Agreement shall remain in full force and effect  regardless of any investigation
made by or on behalf  of any  person,  and shall  survive  the  delivery  of and
payment for the Senior Notes hereunder.

     6. Warranties of  Underwriters:  Each  Underwriter  warrants and represents
that  the   information   furnished  in  writing  to  the  Company  through  the
Representative for use in the Registration  Statement,  in the Basic Prospectus,
in the Prospectus, or in the Prospectus as amended or supplemented is correct as
to such  Underwriter.  The warranties and  representations  of such  Underwriter
contained in this Agreement shall remain in full force and effect  regardless of
any investigation made by or on behalf of the Company or other person, and shall
survive the delivery of and payment for the Senior Notes hereunder

     7. Indemnification and Contribution:

     (a)  To the extent  permitted by law, the Company  agrees to indemnify  and
          hold you harmless,  your  officers and  directors and each person,  if
          any,  who  controls  you within the  meaning of Section 15 of the Act,
          against any and all losses, claims,  damages or liabilities,  joint or
          several,  to which you, they or any of you or them may become  subject
          under the Act or otherwise,  and to reimburse you and such controlling
          person or persons, if any, for any legal or other expenses incurred by
          you or them in connection  with defending any action,  insofar as such
          losses,  claims,  damages,  liabilities or actions arise out of or are
          based upon any  alleged  untrue  statement  or untrue  statement  of a
          material fact contained in the  Registration  Statement,  in the Basic
          Prospectus (if used prior to the effective date of this Agreement), or
          in the  Prospectus,  or if the  Company  shall  furnish or cause to be
          furnished to you any amendments or any  supplements to the Prospectus,
          in the Prospectus as so amended or  supplemented  except to the extent
          that such amendments or supplements  relate solely to securities other
          than  the  Senior  Notes  (provided  that if such  Prospectus  or such
          Prospectus,  as amended or  supplemented,  is used after the period of
          time  referred  to in  Section  4(b)  hereof,  it shall  contain  such
          amendments or  supplements  as the Company  deems  necessary to comply
          with Section  10(a) of the Act), or arise out of or are based upon any
          alleged omission or omission to state therein a material fact required
          to be stated therein or necessary to make the  statements  therein not
          misleading,   except   insofar  as  such  losses,   claims,   damages,
          liabilities or actions arise out of or are based upon any such alleged
          untrue  statement or omission,  or untrue  statement or omission which
          was made in the Registration  Statement, in the Basic Prospectus or in
          the Prospectus, or in the Prospectus as so amended or supplemented, in
          reliance upon and in conformity with information  furnished in writing
          to the  Company by or through  the  Representative  expressly  for use
          therein or with any  statements in or omissions  from that part of the
          Registration   Statement  that  shall   constitute  the  Statement  of
          Eligibility  under the Trust  Indenture Act of any  indenture  trustee
          under an  indenture  of the  Company,  and except that this  indemnity
          shall not inure to your benefit (or of any person  controlling you) on
          account of any losses, claims, damages, liabilities or actions arising
          from the sale of the Senior  Notes to any  person if such loss  arises
          from the fact that a copy of the  Prospectus,  as the same may then be
          supplemented  or amended to the extent such Prospectus was provided to
          you by the Company (excluding, however, any document then incorporated
          or deemed incorporated therein by reference), was not sent or given by
          you to such person with or prior to the  written  confirmation  of the
          sale involved and the alleged  omission or alleged untrue statement or
          omission  or untrue  statement  was  corrected  in the  Prospectus  as
          supplemented  or  amended at the time of such  confirmation,  and such
          Prospectus, as amended or supplemented, was timely delivered to you by
          the Company.  You agree  promptly  after the receipt by you of written
          notice of the commencement of any action in respect to which indemnity
          from the Company on account of its agreement contained in this Section
          7(a) may be sought by you, or by any person controlling you, to notify
          the Company in writing of the commencement  thereof, but your omission
          so to notify the  Company of any such  action  shall not  release  the
          Company  from  any  liability  which  it may  have  to you or to  such
          controlling   person  otherwise  than  on  account  of  the  indemnity
          agreement  contained  in this  Section  7(a).  In case any such action
          shall be brought  against you or any such person  controlling  you and
          you shall  notify the Company of the  commencement  thereof,  as above
          provided, the Company shall be entitled to participate in, and, to the
          extent that it shall wish,  including  the  selection of counsel (such
          counsel to be reasonably  acceptable  to the  indemnified  party),  to
          direct the  defense  thereof at its own  expense.  In case the Company
          elects to direct such  defense and select such  counsel  (hereinafter,
          Company's counsel), you or any controlling person shall have the right
          to  employ  your own  counsel,  but,  in any such  case,  the fees and
          expenses  of such  counsel  shall be at your  expense  unless  (i) the
          Company  has agreed in writing to pay such fees and  expenses  or (ii)
          the named parties to any such action (including any impleaded parties)
          include both you or any controlling  person and the Company and you or
          any controlling  person shall have been advised by your counsel that a
          conflict  of interest  between the Company and you or any  controlling
          person may arise (and the Company's  counsel  shall have  concurred in
          good faith with such  advice) and for this reason it is not  desirable
          for the Company's counsel to represent both the indemnifying party and
          the indemnified party (it being understood,  however, that the Company
          shall not, in  connection  with any one such  action or  separate  but
          substantially  similar  or related  actions  in the same  jurisdiction
          arising  out of the same  general  allegations  or  circumstances,  be
          liable for the reasonable  fees and expenses of more than one separate
          firm of attorneys  for you or any  controlling  person (plus any local
          counsel retained by you or any controlling  person in their reasonable
          judgment), which firm (or firms) shall be designated in writing by you
          or any controlling person).

     (b)  Each Underwriter agrees, to the extent permitted by law, severally and
          not jointly,  to  indemnify,  hold harmless and reimburse the Company,
          its  directors  and such of its  officers  as shall  have  signed  the
          Registration  Statement,  and each  person,  if any,  who controls the
          Company  within the  meaning  of  Section  15 of the Act,  to the same
          extent  and upon the same  terms  as the  indemnity  agreement  of the
          Company set forth in Section  7(a)  hereof,  but only with  respect to
          untrue statements or alleged untrue statements or omissions or alleged
          omissions  made  in  the  Registration  Statement,  or  in  the  Basic
          Prospectus,  or in the Prospectus,  or in the Prospectus as so amended
          or  supplemented,  in reliance upon and in conformity with information
          furnished in writing to the Company by the Representative on behalf of
          such  Underwriter  expressly  for  use  therein.  The  Company  agrees
          promptly after the receipt by it of written notice of the commencement
          of any  action in respect  to which  indemnity  from you on account of
          your  agreement  contained  in this  Section 7(b) may be sought by the
          Company,  or by any person  controlling the Company,  to notify you in
          writing of the commencement  thereof, but the Company's omission so to
          notify you of any such action shall not release you from any liability
          which  you may  have to the  Company  or to  such  controlling  person
          otherwise than on account of the indemnity agreement contained in this
          Section 7(b).

     (c)  If recovery is not  available or  insufficient  under  Section 7(a) or
          7(b)  hereof  for any  reason  other than as  specified  therein,  the
          indemnified  party shall be entitled to  contribution  for any and all
          losses,  claims,  damages,  liabilities  and  expenses  for which such
          indemnification  is so unavailable or insufficient  under this Section
          7(c).  In  determining  the  amount  of  contribution  to  which  such
          indemnified  party is entitled,  there shall be considered the portion
          of the  proceeds of the  offering of the Senior  Notes  realized,  the
          relative  knowledge and access to  information  concerning  the matter
          with  respect  to which the claim was  asserted,  the  opportunity  to
          correct and prevent  any  statement  or  omission,  and any  equitable
          considerations  appropriate under the  circumstances.  The Company and
          the Underwriters agree that it would not be equitable if the amount of
          such contribution were determined by pro rata or per capita allocation
          (even if the Underwriters were treated as one entity for such purpose)
          without  reference  to the  considerations  called for in the previous
          sentence.  No Underwriter or any person  controlling  such Underwriter
          shall be obligated to contribute any amount or amounts hereunder which
          in the aggregate exceeds the total price of the Senior Notes purchased
          by such Underwriter under this Agreement, less the aggregate amount of
          any damages which such  Underwriter and its  controlling  persons have
          otherwise  been  required  to pay in  respect of the same claim or any
          substantially   similar   claim.   No  person   guilty  of  fraudulent
          misrepresentation  (within  the  meaning of Section  11(f) of the Act)
          shall be entitled to  contribution  from any person who was not guilty
          of such fraudulent  misrepresentation.  An Underwriter's obligation to
          contribute  under  this  Section 7 is in  proportion  to its  purchase
          obligation and not joint with any other Underwriter.

     (d)  No indemnifying party shall,  without the prior written consent of the
          indemnified  parties,  settle or compromise or consent to the entry of
          any judgment with respect to any litigation,  or any  investigation or
          proceeding  by  any   governmental   agency  or  body,   commenced  or
          threatened,  or any claim whatsoever in respect of which  contribution
          could be sought under this  Section 7 (whether or not the  indemnified
          parties  are  actual  or  potential  parties  thereto),   unless  such
          settlement,  compromise  or  consent  (i)  includes  an  unconditional
          release of each  indemnified  party from all liability  arising out of
          such litigation, investigation,  proceeding or claim and (ii) does not
          include a statement as to or an admission of fault,  culpability  or a
          failure to act by or on behalf of such indemnified party.

     (e)  In no  event  shall  any  indemnifying  party  have any  liability  or
          responsibility  in  respect of the  settlement  or  compromise  of, or
          consent to the entry of any  judgment  with respect to, any pending or
          threatened action or claim effected without its prior written consent.

     The  agreements  contained  in this  Section 7 hereof  shall remain in full
force and effect  regardless  of any  investigation  made by or on behalf of any
person,  and shall  survive the  delivery  of and  payment for the Senior  Notes
hereunder.

     8. Default of Underwriters:  If any Underwriter  under this Agreement shall
fail or  refuse  (otherwise  than for some  reason  sufficient  to  justify,  in
accordance  with the  terms  hereof,  the  cancellation  or  termination  of its
obligations  hereunder) to purchase and pay for the  principal  amount of Senior
Notes which it has agreed to purchase and pay for  hereunder,  and the aggregate
principal   amount  of  Senior  Notes  which  such  defaulting   Underwriter  or
Underwriters agreed but failed or refused to purchase is not more than one-tenth
of the aggregate  principal amount of the Senior Notes,  the other  Underwriters
shall be  obligated  severally  in the  proportions  which the amounts of Senior
Notes set forth  opposite  their names in Exhibit 1 hereto bear to the aggregate
principal  amount of  Senior  Notes  set  forth  opposite  the names of all such
non-defaulting Underwriters,  to purchase the Senior Notes which such defaulting
Underwriter  or  Underwriters  agreed but failed or refused to  purchase  on the
terms set forth herein;  provided that in no event shall the principal amount of
Senior Notes which any Underwriter has agreed to purchase  pursuant to Section 1
hereof  be  increased  pursuant  to this  Section  8 by an  amount  in excess of
one-ninth of such principal  amount of Senior Notes without the written  consent
of such Underwriter.  If any Underwriter or Underwriters shall fail or refuse to
purchase  Senior Notes and the aggregate  principal  amount of Senior Notes with
respect to which such default  occurs is more than  one-tenth  of the  aggregate
principal amount of the Senior Notes then this Agreement shall terminate without
liability on the part of any non-defaulting Underwriter; provided, however, that
the non-defaulting Underwriters may agree, in their sole discretion, to purchase
the Senior Notes which such defaulting  Underwriter or  Underwriters  agreed but
failed or refused to purchase on the terms set forth herein. In the event of any
such  termination,  the  Company  shall  not  be  under  any  liability  to  any
Underwriter (except to the extent, if any, provided in Section 4(h) hereof), nor
shall any  Underwriter  (other  than an  Underwriter  who shall  have  failed or
refused to purchase the Senior Notes without some reason  sufficient to justify,
in  accordance  with  the  terms  hereof,  its  termination  of its  obligations
hereunder) be under any liability to the Company or any other Underwriter.

     Nothing herein contained shall release any defaulting  Underwriter from its
liability  to  the  Company  or  any  non-defaulting   Underwriter  for  damages
occasioned by its default hereunder.

     9.  Termination  of Agreement by the  Underwriters:  This  Agreement may be
terminated at any time prior to the Time of Purchase by the  Representative  if,
after the  execution  and  delivery of this  Agreement  and prior to the Time of
Purchase, in the Representative's reasonable judgment, the Underwriters' ability
to market  the  Senior  Notes  shall  have been  materially  adversely  affected
because:

          (i) trading in  securities on the New York Stock  Exchange  shall have
     been  generally  suspended  by the  Commission  or by the  New  York  Stock
     Exchange  or  trading  in the  securities  of the  Company  shall have been
     suspended by the New York Stock Exchange, or

          (ii)  there  shall  have   occurred  any  outbreak  or  escalation  of
     hostilities,  declaration  by the United States of a national  emergency or
     war or other national or international calamity or crisis, or

          (iii) a general banking moratorium shall have been declared by Federal
     or New York State authorities, or

          (iv)  there  shall  have  been  any  decrease  in the  ratings  of the
     Company's debt securities by Moody's Investors Services,  Inc. (Moody's) or
     Standard  & Poor's  Ratings  Group  (S&P) or  either  Moody's  or S&P shall
     publicly announce that it has such debt securities under  consideration for
     possible downgrade.

     If the  Representative  elects to terminate this Agreement,  as provided in
this Section 9, the Representative will promptly notify the Company by telephone
or by telex or facsimile  transmission,  confirmed in writing. If this Agreement
shall not be carried out by any Underwriter for any reason permitted  hereunder,
or if the sale of the Senior Notes to the  Underwriters  as herein  contemplated
shall not be carried  out  because  the  Company is not able to comply  with the
terms hereof, the Company shall not be under any obligation under this Agreement
and shall not be liable to any Underwriter or to any member of any selling group
for the loss of anticipated  profits from the transactions  contemplated by this
Agreement (except that the Company shall remain liable to the extent provided in
Section  4(h)  hereof) and the  Underwriters  shall be under no liability to the
Company nor be under any liability under this Agreement to one another.

     10.  Notices:  All notices  hereunder  shall,  unless  otherwise  expressly
provided, be in writing and be delivered at or mailed to the following addresses
or by telex or  facsimile  transmission  confirmed  in writing to the  following
addresses:  if to the  Underwriters,  to the  Representative  at Merrill  Lynch,
Pierce,  Fenner & Smith  Incorporated,  4 World Financial Center,  Floor 24, New
York, New York 10080, Attention: Robert D. Craig (fax 212/449-8636),  at Salomon
Smith Barney Inc., 388 Greenwich  Street,  New York, New York 10013,  Attention:
Henry A. Clark III (fax  212/816-0900),  and UBS Warburg  LLC,  299 Park Avenue,
Suite 38th  Floor,  New York,  New York  10171,  Attention:  David  Mikula  (fax
214/821-2467),  and, if to the Company,  to Public Service  Company of Oklahoma,
c/o American Electric Power Service  Corporation,  1 Riverside Plaza,  Columbus,
Ohio 43215, Attention: A. A. Pena, Treasurer, (fax 614/223-1687).

     11.  Parties in Interest:  The  agreement  herein set forth has been and is
made solely for the benefit of the  Underwriters,  the  Company  (including  the
directors  thereof  and such of the  officers  thereof as shall have  signed the
Registration Statement), the controlling persons, if any, referred to in Section
7  hereof,   and   their   respective   successors,   assigns,   executors   and
administrators, and, except as expressly otherwise provided in Section 8 hereof,
no other person  shall  acquire or have any right under or by the virtue of this
Agreement.

     12. Definition of Certain Terms: If there be two or more persons,  firms or
corporations named in Exhibit 1 hereto, the term "Underwriters", as used herein,
shall be deemed to mean the several  persons,  firms or  corporations,  so named
(including the  Representative  herein mentioned,  if so named) and any party or
parties substituted pursuant to Section 8 hereof, and the term "Representative",
as used herein,  shall be deemed to mean the  representative or  representatives
designated by, or in the manner authorized by, the Underwriters. All obligations
of the Underwriters  hereunder are several and not joint. If there shall be only
one  person,   firm  or  corporation  named  in  Exhibit  1  hereto,   the  term
"Underwriters" and the term  "Representative",  as used herein,  shall mean such
person,  firm or  corporation.  The term  "successors" as used in this Agreement
shall not include any purchaser,  as such purchaser,  of any of the Senior Notes
from any of the respective Underwriters.

     13. Conditions of the Company's Obligations: The obligations of the Company
hereunder  are subject to the  Underwriters'  performance  of their  obligations
hereunder,  and the further  condition that at the Time of Purchase the Oklahoma
State  Corporation  Commission shall have issued an appropriate  order, and such
order  shall  remain in full  force and  effect,  authorizing  the  transactions
contemplated hereby.

     14.  Applicable  Law:  This  Agreement  will be governed  and  construed in
accordance with the laws of the State of New York.

     15.  Execution of  Counterparts:  This Agreement may be executed in several
counterparts,  each of which shall be  regarded as an original  and all of which
shall constitute one and the same document.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]



         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed by their respective officers thereunto duly authorized, on the date
first above written.

                                    PUBLIC SERVICE COMPANY OF OKLAHOMA


                                    By:    /s/ G. S. Chatas
                                            G. S. Chatas
                                            Assistant Treasurer

MERRILL LYNCH, PIERCE, FENNER &
     SMITH INCORPORATED

By:  /s/ John E. Lynch
Name:    John E. Lynch
Title:   Vice President


SALOMON SMITH BARNEY INC.

By:    /s/Howard Hiller
Name:     Howard Hilller
Title:  Managing Director


UBS WARBURG LLC

By:   /s/ Christopher Forshner      /s/ Ryan Donovan
Name:  Christopher Forshner             Ryan Donovan
Title: Executive Director           Associate Director

as Representatives and on behalf of
the Underwriters named in Exhibit 1 hereto





                                    EXHIBIT 1

                                                              Principal Amount
 Underwriter                                                   of Senior Notes


UBS Warburg LLC...............................................$  49,650,000
Merrill Lynch, Pierce, Fenner & Smith Incorporated............   49,625,000
Salomon Smith Barney Inc......................................   49,625,000
ABN AMRO Incorporated.........................................    9,750,000
Danske Securities (US), Inc...................................    9,750,000
A.G. Edwards & Sons, Inc......................................    1,500,000
Charles Schwab & Co., Inc.....................................    1,500,000
CIBC World Markets Corp.......................................    1,500,000
Deutsche Banc Alex. Brown Inc.................................    1,500,000
Fahenstock & Co. Inc..........................................    1,500,000
H & R BLOCK Financial Advisors, Inc...........................    1,500,000
HSBC Securities USA, Inc......................................    1,500,000
McDonald Investments Inc., a KeyCorp Company..................    1,500,000
Prudential Securities Incorporated............................    1,500,000
Quick & Reilly, Inc...........................................    1,500,000
Raymond James & Associates, Inc...............................    1,500,000
RBC Dain Rauscher Inc.........................................    1,500,000
TD Waterhouse Investor Services, Inc..........................    1,500,000
First Union Securities, Inc...................................    1,500,000
Wells Fargo Van Kasper LLC....................................    1,500,000
Banc of America Securities LLC................................      700,000
D.A. Davidson & Co............................................      700,000
Ferris, Baker Watts, Incorporated.............................      700,000
Fidelity Capital Markets......................................      700,000
Janney Montgomery Scott LLC...................................      700,000
J.J.B Hilliard, W.L. Lyons, Inc...............................      700,000
Legg Mason Wood Walker, Incorporated..........................      700,000
Morgan Keegan & Company, Inc..................................      700,000
Muriel Siebert & Co...........................................      700,000
Robert W. Baird & Co. Incorporated............................      700,000
Ryan, Beck & Co. LLC .........................................      700,000
The Williams Capital Group, L.P...............................      700,000
Utendahl Capital Partners, L.P................................      700,000
                                                                ------------
                                                               $200,000,000





                                                                   EXHIBIT 4(a)

===============================================================================







                       PUBLIC SERVICE COMPANY OF OKLAHOMA


                                       and


                              THE BANK OF NEW YORK,
                                   AS TRUSTEE


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


                          SECOND SUPPLEMENTAL INDENTURE

                          Dated as of November 26, 2002


                          Supplemental to the Indenture
                          dated as of November 1, 2000





                       6% Senior Notes, Series B, Due 2032





===============================================================================



     SECOND  SUPPLEMENTAL  INDENTURE,  dated as of November  26,  2002,  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 $200,000,000 to be designated the "6% Senior Notes,  Series
B, Due 2032" (the  "Series B Notes"),  and all action on the part of the Company
necessary  to  authorize  the  issuance of the Series B Notes under the Original
Indenture and this Second Supplemental Indenture has been duly taken.

     All acts and things necessary to make the Series B Notes,  when executed by
the  Company  and  completed,  authenticated  and  delivered  by the  Trustee as
provided in the Original Indenture and this Second 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 SECOND SUPPLEMENTAL INDENTURE WITNESSETH:

     That in consideration of the premises and of the acceptance and purchase of
the Series B 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 Series B 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 Series B Notes attached hereto as Exhibit A.

                                   ARTICLE TWO
          Terms and Issuance of the 6% Senior Notes, Series B, Due 2032

SECTION 201. Issue of the Series B Notes.

     A series of Senior Notes which shall be  designated  the "6% Senior  Notes,
Series B, Due 2032" 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 Second Supplemental
Indenture (including the form of Global Security set forth in Exhibit A hereto).
The aggregate  principal  amount of the Series B Notes to be  authenticated  and
delivered  shall  be  $200,000,000,  and no  further  Series  B Notes  shall  be
authenticated  and  delivered,  except as  permitted  by the  provisions  of the
Original Indenture.


SECTION 202. Form of Series B Notes; Incorporation of Terms.

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


SECTION 203. Depositary for Global Securities.

     The Depositary for any Global Securities of the series of which this Series
B 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  Series B 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.





SECTION 205. Optional Redemption.

     Subject to the terms of Article Eleven of the Indenture,  the Company shall
have the right to redeem the Series B Notes at its  option,  without  premium or
penalty,  in whole or, in part, at any time on or after  November 26, 2007, at a
redemption price equal to 100% of the principal amount redeemed plus any accrued
but unpaid interest to the date of such redemption.

SECTION 206. Mandatory Redemption.

     (a) The Series B Notes shall be  redeemed  in the event  (i)(A) the Company
reorganizes, or otherwise transfers a substantial portion of its assets, and (B)
that  reorganization  or  transfer  results  in the  Company  no longer  being a
regulated  utility  company,  and  (C) the  Series  B  Notes  and the  Company's
obligations under the Indenture are not assumed by, and do not become the direct
and primary obligations of, a regulated utility company,  unless Ambac Assurance
Corporation  ("Ambac")  consents to such  reorganization  or transfer,  (ii) the
Company  fails to pay to Ambac an insurance  premium  pursuant to the  Insurance
Agreement,  dated as of November 26, 2002 (the "Insurance  Agreement"),  between
the  Company and Ambac  unless  Ambac  waives such  failure or (iii) the Company
incurs or issues  additional  indebtedness  for  borrowed  money  secured by its
assets  and  fails to  secure  its  repayment  obligations  to Ambac  under  the
Insurance Agreement unless Ambac waives such failure.

     (b) If the Series B Notes are  redeemed  pursuant to this Section 205 on or
after  November 26, 2007,  the  redemption  price will be 100% of the  principal
amount of the Series B Notes plus  accrued  and unpaid  interest  thereon to the
date of redemption.

     (c) If the Series B Notes are redeemed  pursuant to this Section 205 before
November 26, 2007, the redemption price will be equal to the accrued interest on
the Series B Notes to the date of  redemption  plus the  greater of: (i) 100% of
the  principal  amount of the  Series B Notes;  and (ii) the sum of the  present
value of the  principal  amount of the Series B Notes  together with the present
values  of the  scheduled  payments  of  interest  on the  Series  B Notes  (not
including  any portion of such  payments  of interest  accrued as of the date of
redemption) from the date of redemption to the interest payment date on December
31,  2007 (such time  period  between the date of  redemption  and the  interest
payment date on December 31, 2007 being referred to as the "Remaining Term"), in
each case  discounted to the date of redemption on a quarterly basis (assuming a
360-day year  consisting of twelve 30-day months) at the Adjusted  Treasury Rate
plus twenty-five (25) basis points,  as calculated by an Independent  Investment
Banker.

     "Adjusted Treasury Rate" means, with respect to any redemption rate (i) the
yield,  under the heading  which  represents  the  average  for the  immediately
preceding week,  appearing in the most recently  published  statistical  release
designated "H.15(519)" or any successor publication which is published weekly by
the Board of  Governors  of the  Federal  Reserve  System and which  establishes
yields on actively traded United States Treasury securities adjusted to constant
maturity  under the caption  "Treasury  Constant  Maturities",  for the maturity
corresponding  to the Comparable  Treasury Issue (if no maturity is within three
months  before  or  after  the  Remaining  Term,  yields  for the two  published
maturities most closely  corresponding to the Comparable Treasury issue shall be
determined and the adjusted  Treasury Rate shall be interpolated or extrapolated
from such yields on a straight line basis,  rounding to the nearest  month);  or
(ii) if such release (or any successor release) is not published during the week
preceding  the  calculation  date or does not contain such yields,  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.  The Adjusted  Treasury Rate shall be
calculated on the third business day preceding the redemption date.

     "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  securities to be redeemed 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 Series B Notes.

     "Comparable  Treasury  Price"  means  (1) the  average  of  five  Reference
Treasury Dealer Quotations for such Redemption Date, after excluding the highest
and lowest  Reference  Treasury  Dealer  Quotations,  or (2) if the  Independent
Investment  Banker  obtains  fewer  than five  such  Reference  Treasury  Dealer
Quotations, the average of all such quotations.

     "Independent Investment Banker" means one of the Reference Treasury Dealers
appointed by us.

     "Reference Treasury Dealer" means (I) each of Merrill Lynch, Pierce, Fenner
& Smith  Incorporated,  Salomon Smith Barney Inc. and UBS Warburg LLC, and their
respective  successors;  provided  that, if any of the foregoing  ceases to be a
primary  U.S.  Government  securities  dealer in the United  States (a  "Primary
Treasury Dealer"),  the Company will substitute another Primary Treasury Dealer;
and (II) any other Primary Treasury Dealer selected by the Company.

     "Reference   Treasury  Dealer  Quotations"  means,  with  respect  to  each
Reference Treasury Dealer and any redemption date, the average, as determined by
the  Independent  Investment  Banker,  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 Independent Investment Banker at 5:00
p.m., New York City time, on the third  business day preceding  such  redemption
date.

SECTION 207. The Insurer.

     To the extent  permitted by law and so long as Ambac is in compliance  with
its obligations under its Financial  Guaranty  Insurance Policy No. 20300BE (the
"Financial Guaranty Insurance Policy"),  the Financial Guaranty Insurance Policy
is in full  force  and  effect  and  Ambac  is not  subject  to any  bankruptcy,
insolvency or similar proceedings:

          (i) any provision of this Second Supplemental Indenture,  any Series B
     Note or the Indenture  (collectively,  the "Financing Documents") expressly
     recognizing  or  granting  rights in or to Ambac may not be  amended in any
     manner which affects the rights of Ambac  hereunder or  thereunder  without
     the prior written consent of Ambac.

          (ii) Ambac shall be deemed to be the owner of all outstanding Series B
     Notes for all  purposes  (including,  without  limitation,  all  approvals,
     consents,  requests,  waivers,  authorizations,   directions,  inspections,
     appointments and the institution of any action),  provided, that nothing in
     this  clause  (ii) shall  impair  the  rights of any of the  holders of the
     Series B Notes (the  "Securityholders")  to receive all  payments due under
     the Series B Notes.  Ambac's  consent shall be required with respect to (a)
     the execution and delivery of any  supplemental  indenture to the Indenture
     for which the consent of the Securityholders is required, or any amendment,
     supplement or change to or modification of any Financing  Document  (except
     as otherwise  provided by Section 901 of the Indenture) and (b) the removal
     of the Trustee or any paying agent and  selection  and  appointment  of any
     successor trustee or paying agent.

          (iii)  Any   reorganization   or  liquidation  plan  under  applicable
     bankruptcy  law or  similar  law  with  respect  to  the  Company  must  be
     acceptable  to  Ambac.  In  the  event  of  any  such   reorganization   or
     liquidation,  Ambac  shall  have  the  right  to  vote  on  behalf  of  all
     Securityholders  who hold Ambac-insured  Series B Notes absent a default by
     Ambac under the applicable  Financial  Guaranty  Insurance  Policy insuring
     such Series B Notes.

          (iv)   Anything   in  any   Financing   Document   to   the   contrary
     notwithstanding,  upon  the  occurrence  and  continuance  of an  Event  of
     Default,  Ambac shall be entitled to control and direct the  enforcement of
     all rights and remedies granted to the  Securityholders  or the Trustee for
     the  benefit  of  the  Securityholders   under  the  Financing   Documents,
     including, without limitation: (A) the right to accelerate the principal of
     the  Series B Notes as  described  in the  Indenture,  and (B) the right to
     annul any declaration of acceleration,  and Ambac shall also be entitled to
     approve all waivers of Events of Default with  respect to or effecting  the
     Series B Notes.

          (v) While the Financial  Guaranty  Insurance Policy is in effect,  the
     Company (and/or the Trustee,  where indicated below) shall furnish to Ambac
     (to  the  attention  of  the  Surveillance  Department,   unless  otherwise
     indicated):

               (a) as soon as practicable  after the filing  thereof,  a copy of
          any  financial  statement  of the  Company and a copy of any audit and
          annual report of the Company;

               (b) such additional information it may reasonably request;

               (c)  a  copy  of  any  notice  to  be  given  to  the  registered
          Securityholders,   including,   without  limitation,   notice  of  any
          redemption or defeasance  of the Series B Notes,  and any  certificate
          rendered  pursuant to any Financing  Document relating to the Series B
          Notes, which obligation shall bind the Trustee as well as the Company;

               (d) notice  (attention:  General  Counsel)  by the Trustee of any
          failure of the Company to provide relevant notices, certificates, etc.
          under the Financing Documents; and

               (e)   notwithstanding   any  other  provision  of  any  Financing
          Document, immediate notice (attention: General Counsel) if at any time
          there are insufficient moneys to make any payments of principal and/or
          interest on the Series B Notes as required and immediate notice of the
          occurrence of any Event of Default,  which  obligation  shall bind the
          Trustee as well as the Company.

          (vi)  Notwithstanding  anything  herein  or  in  any  other  Financing
     Document to the contrary,  in the event that the principal  and/or interest
     due on the Series B Notes shall be paid by Ambac  pursuant to the Financial
     Guaranty   Insurance   Policy,   (a)  the  Series  B  Notes  shall   remain
     "outstanding"  for all  purposes  under the  Indenture,  not be  considered
     defeased or otherwise  satisfied and not be considered paid by the Company,
     (b) except as expressly stated herein or otherwise agreed or undertaken (I)
     the Paying Agent,  if any, shall have no duties or obligations  relating to
     any payments made by Ambac and (II) the Trustee shall not be deemed to have
     knowledge  of any default  unless the  Trustee  shall have  written  notice
     thereof,  (c) the assignment and pledge of the Indenture and all covenants,
     agreements  and other  obligations  of the  Company to the  Securityholders
     shall  continue  to exist and shall run to the  benefit  of Ambac,  and (d)
     Ambac  shall be  subrogated  to the rights of such  Securityholders  to the
     extent of such payment.

          (vii) As long as the Financial  Guaranty  Insurance Policy shall be in
     full force and effect, the Company,  the Trustee and any Paying Agent agree
     to comply with the following provisions:

               (a) at least one (1) day prior to all Interest  Payment Dates the
          Trustee or Paying Agent, if any, will determine  whether there will be
          sufficient  funds available to pay the principal of or interest on the
          Series B Notes on such Interest Payment Date. If the Trustee or Paying
          Agent,  if any,  determines  that  there  will be  insufficient  funds
          available, the Trustee or Paying Agent, if any, shall so notify Ambac.
          Such notice shall  specify the amount of the  anticipated  deficiency,
          the Series B Notes to which such  deficiency is applicable and whether
          such Series B Notes will be deficient as to principal or interest,  or
          both.  If the  Trustee or Paying  Agent,  if any,  has not so notified
          Ambac at least one (1) day prior to an Interest  Payment  Date,  Ambac
          will make  payments of principal or interest due on the Series B Notes
          on or before  the first  (1st)  day next  following  the date on which
          Ambac shall have  received  notice of  nonpayment  from the Trustee or
          Paying Agent, if any.

               (b) the Trustee or Paying  Agent,  if any,  shall,  after  giving
          notice to Ambac as provided in (a) above, make available to Ambac and,
          at Ambac's direction,  to The Bank of New York, in New York, New York,
          as insurance trustee for Ambac or any successor insurance trustee (the
          "Insurance Trustee"), the registration books of the Company maintained
          by the Trustee or Paying  Agent,  if any, and all records  relating to
          the funds and accounts (if any) maintained under the Indenture.

               (c) the Trustee or Paying Agent,  if any, shall provide Ambac and
          the  Insurance  Trustee with a list of  registered  owners of Series B
          Notes  entitled to receive  principal or interest  payments from Ambac
          under the terms of the Financial  Guaranty Insurance Policy, and shall
          pursuant to arrangements with the Insurance Trustee (I) mail checks or
          drafts to the registered  owners of Series B Notes entitled to receive
          full or partial  interest  payments  from Ambac and (II) pay principal
          upon  Series  B Notes  surrendered  to the  Insurance  Trustee  by the
          registered  owners  of  Series B Notes  entitled  to  receive  full or
          partial principal payments from Ambac.

               (d) the Trustee or Paying Agent,  if any,  shall,  at the time it
          provides  notice to Ambac  pursuant  to (a) above,  notify  registered
          owners of Series B Notes  entitled to receive the payment of principal
          or interest thereon from Ambac (I) as to the fact of such entitlement,
          (II) that Ambac will remit to them,  through the Insurance  Trustee or
          pursuant to arrangements  made with the Insurance  Trustee through the
          Trustee  or  Paying  Agent,  if  any,  all or a part  of the  interest
          payments next coming due upon proof of  Securityholder  entitlement to
          interest  payments  and  delivery to the  Insurance  Trustee,  in form
          satisfactory to the Insurance Trustee, of an appropriate assignment of
          the  registered  owner's  right to payment,  (III) that should they be
          entitled to receive full payment of  principal  from Ambac,  they must
          surrender  their Series B Notes (along with an appropriate  instrument
          of assignment in form  satisfactory to the Insurance Trustee to permit
          ownership  of such  Series  B Notes  to be  registered  in the name of
          Ambac) for payment to the Insurance Trustee,  who shall then pass such
          Series B Notes on to the Trustee or Paying Agent,  if any, for payment
          of  principal  upon such  Series B Notes and (IV) that  should they be
          entitled to receive  partial  payment of  principal  from  Ambac,  for
          payment of principal on such Series B Notes they must surrender  their
          Series B Notes for  payment  thereon  first to the  Trustee  or Paying
          Agent,  if any,  who shall note on such  Series B Notes the portion of
          the principal  paid by the Trustee or Paying Agent,  if any, and then,
          along  with  an   appropriate   instrument   of   assignment  in  form
          satisfactory to the Insurance Trustee, to the Insurance Trustee, which
          will then make  arrangements  with the Trustee or the Paying Agent, if
          any, for the payment of the unpaid portion of principal.

               (e) in the event that the Trustee or Paying  Agent,  if any,  has
          notice that any payment of principal of or interest on a Series B Note
          which has become Due for Payment (as defined in the Financial Guaranty
          Insurance  Policy)  and  which  is made to a  Securityholder  by or on
          behalf of the  Company  has been deemed a  preferential  transfer  and
          theretofore recovered from its registered owner pursuant to the United
          States  Bankruptcy  Code by a trustee in bankruptcy in accordance with
          the  final,   nonappealable   order  of  a  court   having   competent
          jurisdiction,  the Trustee or Paying Agent, if any, shall, at the time
          Ambac is notified pursuant to (a) above,  notify all registered owners
          that in the event that any registered owner's payment is so recovered,
          such  registered  owner will be entitled to payment  from Ambac to the
          extent  of  such  recovery  if  sufficient  funds  are  not  otherwise
          available,  and the Trustee or Paying Agent,  if any, shall furnish to
          Ambac its records evidencing the payments of principal of and interest
          on the Series B Notes  which  have been made by the  Trustee or Paying
          Agent, if any, and subsequently  recovered from registered  owners and
          the dates on which such payments were made.

               (f) in addition to those rights granted Ambac under the Financing
          Documents, Ambac shall, to the extent it makes payment of principal of
          or interest on Series B Notes,  become subrogated to the rights of the
          recipients  of such  payments  in  accordance  with  the  terms of the
          Financial  Guaranty Insurance Policy, and to evidence such subrogation
          (1) in the case of subrogation as to claims for past due interest, the
          Trustee or Paying Agent, if any, shall note Ambac's rights as subrogee
          on the registration  books of the Company maintained by the Trustee or
          Paying Agent,  if any, upon receipt from Ambac of proof of the payment
          of interest  thereon to the  registered  owners of the Series B Notes,
          and  (2)  in the  case  of  subrogation  as to  claims  for  past  due
          principal,  the Trustee or Paying  Agent,  if any,  shall note Ambac's
          rights as subrogee on the registration books of the Company maintained
          by the Trustee or Paying Agent, if any, upon surrender of the Series B
          Notes by the  registered  owners  thereof  together  with proof of the
          payment of principal thereof.

          (viii) The  Trustee  or Paying  Agent,  if any,  may be removed at any
     time, at the request of Ambac, for any breach of its obligations  under the
     Financing Documents.

          (ix) Ambac  shall  receive  prior  written  notice of any  Trustee (or
     Paying Agent) resignation.

          (x) Every successor Trustee appointed  pursuant to the Indenture shall
     be a trust  company or bank in good  standing  located  in or  incorporated
     under  the  laws  of any  State  of the  United  States  of  America,  duly
     authorized to exercise  trust powers and subject to  examination by federal
     or state authority,  having a reported capital and surplus of not less than
     $75,000,000  and  acceptable  to Ambac.  Any  successor  Paying  Agent,  if
     applicable,  shall not be appointed unless Ambac approves such successor in
     writing.

          (xi)  Notwithstanding any other provision of the Financing  Documents,
     in determining whether the rights of the Securityholders  will be adversely
     affected by any action taken  pursuant to the terms and  provisions  of the
     Financing  Documents,  the Trustee (or Paying  Agent)  shall  consider  the
     effect  on the  Securityholders  as if  there  were no  Financial  Guaranty
     Insurance Policy.

          (xii)  Notwithstanding any other provision of the Financing Documents,
     no removal,  resignation  or  termination  of the Trustee (or Paying Agent)
     shall  take  effect  until a  successor,  acceptable  to  Ambac,  shall  be
     appointed.

          (xiii) To the extent that the Financing  Documents confer upon or give
     or grant to Ambac  any  right,  remedy  or claim  thereunder  or by  reason
     thereof,  Ambac is  hereby  explicitly  recognized  as being a  third-party
     beneficiary  thereunder  and may  enforce  any such  right  remedy or claim
     conferred, given or granted thereunder.

          (xiv) Nothing in the  Financing  Documents,  expressed or implied,  is
     intended or shall be construed to confer upon,  or to give or grant to, any
     person or entity,  other than the Company,  the Trustee,  Ambac, the Paying
     Agent,  if any, and the registered  Securityholders,  any right,  remedy or
     claim  under or by  reason  of the  Financing  Documents  or any  covenant,
     condition or stipulation thereof, and all covenants, stipulations, promises
     and agreements in the Financing Documents contained by and on behalf of the
     Company  shall be for the sole and  exclusive  benefit of the Company,  the
     Trustee,   Ambac,   the  Paying   Agent,   if  any,   and  the   registered
     Securityholders.

          (xv) The  Company  may not  elect  to  defease  the  Series B Notes in
     accordance  with Section 401, 403 or 1009 of the Indenture  without  having
     obtained  the prior  written  consent  of  Ambac,  such  consent  not to be
     unreasonably  withheld. No such defeasance shall be effected by the deposit
     or delivery of U.S.  Government  Obligations  with or to the Trustee unless
     the securities or instruments  used for such purpose would constitute "U.S.
     Government Obligations" under clause (i) of the definition of such term.

SECTION 208. Events of Default.

     It shall be an Event  of  Default  under  the  Indenture  if an  "Event  of
Default" shall have occurred and be continuing under the Insurance Agreement. If
Ambac waives an Event of Default under the Insurance  Agreement or such Event of
Default is cured,  then such  Event of  Default  will not be an Event of Default
with respect to the Series B Notes under the Indenture.

SECTION 209. Sinking Funds.

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

SECTION 210. Regular Record Date.

     The "Regular Record Date" will be the close of business on the Business Day
prior  to the  relevant  interest  payment  date,  except  that  the  notes  are
certificated,  the  "Regular  Record Date" shall be the close of business on the
March  15,  June 15,  September  15 or  December  15,  as the case may be,  next
preceding an interest payment date or if such March 15, June 15, September 15 or
December 15 is not a Business Day, the next preceding Business Day.

     "Business  Day"  means  any  day  that  is  not  a  day  on  which  banking
institutions in New York City are authorized or required by law or regulation to
close.

                                  ARTICLE THREE
                                  Miscellaneous

SECTION 301. Execution as Supplemental Indenture.

     This Second Supplemental Indenture is executed and shall be construed as an
indenture  supplemental  to the  Original  Indenture  and,  as  provided  in the
Original Indenture, this Second 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 Second  Supplemental
Indenture by any of the  provisions  of the Trust  Indenture  Act, such required
provision   shall   control.

III. 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 Second  Supplemental
Indenture shall bind its successors and assigns, whether so expressed or not.

SECTION 305. Separability Clause.

     In case any  provision  in this  Second  Supplemental  Indenture  or in the
Series  B 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 Second Supplemental Indenture.

     Subject to  Sections  207(xiii)  and (xiv)  hereof,  nothing in this Second
Supplemental  Indenture or in the Series B 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 Second Supplemental Indenture.

SECTION 307. Execution and Counterparts.

     This  Second  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.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]




     IN WITNESS WHEREOF, the parties hereto have caused this Second Supplemental
Indenture  to be duly  executed and  attested,  all as of the day and year first
above written.


                                 PUBLIC SERVICE COMPANY OF OKLAHOMA


                                  By:      /s/ Geoffrey S. Chatas
                                         Name: Geoffrey S. Chatas
                                         Title: Assistant Treasurer

Attest:


/s/ Thomas G. Berkemeyer
Name:    Thomas G. Berkemeyer
Title:   Assistant Secretary

                                   THE BANK OF NEW YORK, as Trustee


                                   By:      /s/ Joseph A. Lloret
                                          Name: Joseph A. Lloret
                                          Title: Assistant Treasurer
Attest:


/s/ Mary LaGumina
Name:    Mary LaGumina
Title:   Vice President




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


     On the 26th day of November,  2002, personally appeared before me, a Notary
Public  within and for said County in the State of Ohio,  Geoffrey S. Chatas and
Thomas  G.  Berkemeyer,  to me  known  and  known to me to be  respectively  the
Assistant  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  Assistant  Treasurer  and  Assistant  Secretary  for and on behalf of said
corporation  and  that the  same is  their  free act and deed as such  Assistant
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 26th day
of November, 2002.



                                                 /s/ Mary M. Soltesz
                                                  Notary Public, State of Ohio



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


     On the 26th day of November,  2002, personally appeared before me, a Notary
Public within and for said County in the State of New York, Joseph A. Lloret and
Mary  LaGumina,  to me known and known to me to be  respectively  the  Assistant
Treasurer and Vice  President 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  Assistant  Treasurer  and Vice
President for and on behalf of said  corporation and that the same is their free
act and deed as such Assistant Treasurer and Vice President,  respectively,  and
the free and corporate act and deed of said corporation.

     In witness whereof, I have hereunto set my hand notarial seal this 26th day
of November, 2000.



                                               /s/ William J. Cassels
                                               Notary Public, State of New York




                                                       EXHIBIT A TO EXHIBIT 4(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 (55 Water Street,  New York, New York) to the issuer or
its agent for registration of transfer, exchange or payment, and any certificate
to be issued is registered in the name of Cede & Co. or in such other name as is
requested by an authorized  representative  of The Depository  Trust Company and
any payment is made to Cede & Co., 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.  Except as otherwise provided
in Section 311 of the Indenture, this Security may be transferred,  in whole but
not in  part,  only to  another  nominee  of the  Depository  or to a  successor
Depository or to a nominee of such successor Depository.

Financial  Guaranty  Insurance Policy No. 20300BE (the "Policy") with respect to
payments due for principal of and interest on this Note has been issued by Ambac
Assurance Corporation ("Ambac Assurance").  The Policy has been delivered to The
Bank of New York, New York, New York, as the Insurance Trustee under said Policy
and will be held by such Insurance Trustee or any successor  insurance  trustee.
The Policy is on file and  available for  inspection at the principal  office of
the Insurance  Trustee and a copy thereof may be secured from Ambac Assurance or
the Insurance  Trustee.  All payments required to be made under the Policy shall
be made in  accordance  with the  provisions  thereof.  The  owner of this  Note
acknowledges  and consents to the subrogation  rights of Ambac Assurance as more
fully set forth in the Policy.

No.  R-1                                                8,000,000 Senior Notes,
                                                      $25 principal amount each

                      PUBLIC SERVICE COMPANY OF OKLAHOMA 6%
                        Senior Notes, Series B, Due 2032

CUSIP:                                   Original Issue Date: November 26, 2002

Stated Maturity:  December 31, 2032                           Interest Rate:  6%

Principal Amount:  $200,000,000
Redeemable:       Yes                No
In Whole:         Yes                No
In Part:          Yes                No
Mandatory Redemption:  At any time and at the redemption prices described herein
Initial Optional Redemption Date:  November 26, 2007
Initial Optional Redemption Price: 100%



     PUBLIC  SERVICE  COMPANY OF OKLAHOMA,  a  corporation  duly  organized  and
existing  under the laws of the State of  Oklahoma  (herein  referred  to as the
"Company",  which term  includes any successor  corporation  under the Indenture
hereinafter  referred to), for value received,  hereby promises to pay to CEDE &
CO. or registered  assigns,  the Principal  Amount specified above on the Stated
Maturity  specified above, and to pay interest on said Principal Amount from the
Original Issue Date  specified  above or from the most recent  interest  payment
date (each such date,  an "Interest  Payment  Date") to which  interest has been
paid or duly provided for,  quarterly in arrears on March 31, June 30, September
30 and December 31 in each year, commencing March 31, 2003, 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, as provided in the Indenture,  as  hereinafter  defined,
shall be paid to the Person in whose name this Note (or one or more  Predecessor
Securities)  shall have been  registered at the close of business on the Regular
Record Date with respect to such Interest Payment Date, which shall be the close
of business on the Business Day next preceding  such Interest  Payment Date. Any
such interest not so punctually  paid or duly provided for shall forthwith cease
to be  payable to the Holder on such  Regular  Record  Date and shall be paid as
provided in said Indenture.

     If any Interest Payment Date, any redemption date or the Stated Maturity is
not a Business  Day,  then  payment of the amounts due on this Note on such date
will be made on the next  succeeding  Business Day, and no interest shall accrue
on such  amounts  for the period  from and after  such  Interest  Payment  Date,
redemption  date or Stated  Maturity,  as the case may be,  except that, if such
Business Day is in the next succeeding calendar year, such payment shall be made
on the immediately  preceding Business Day, with the same force and effect as if
made on such date.  The principal of (and  premium,  if any) and the interest on
this Note shall be payable 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 any
coin or currency of the United States of America which at the time of payment is
legal tender for payment of public and private debts;  provided,  however,  that
payment of interest  (other than interest  payable on the Stated Maturity or any
redemption date) 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.

     This  Note is one of a duly  authorized  series  of  Notes  of the  Company
(herein sometimes referred to as the "Notes"),  specified in the Indenture,  all
issued or to be issued in one or more series  under and pursuant to an Indenture
dated as of November 1, 2000 duly executed and delivered between the Company and
The Bank of New York,  a national  banking  association  organized  and existing
under the laws of the United  States,  as  Trustee  (herein  referred  to as the
"Trustee")  (such  Indenture,  as  originally  executed  and  delivered  and  as
thereafter  supplemented  and  amended  being  hereinafter  referred  to as  the
"Indenture"),  to  which  Indenture  and  all  indentures  supplemental  thereto
reference is hereby made for a description of the rights, limitations of rights,
obligations,  duties and immunities  thereunder of the Trustee,  the Company and
the holders of the Notes. By the terms of the Indenture,  the Notes are issuable
in series which may vary as to amount, date of maturity, rate of interest and in
other respects as in the Indenture  provided.  This Note is one of the series of
Notes designated on the face hereof.

     Subject to the terms of Article Eleven of the Indenture,  the Company shall
have the right to redeem this Note at its option, without premium or penalty, in
whole or, in part,  at any time on or after  November 26, 2007,  at a redemption
price equal to 100% of the principal amount redeemed plus any accrued but unpaid
interest to the date of such redemption.

     This Note shall be redeemable  and at the  redemption  prices to the extent
set forth herein, in the Second  Supplement  Indenture and in the Indenture upon
not less than thirty,  but not more than sixty,  days previous notice by mail to
the registered owner.

     To the extent  permitted by law and so long as Ambac is in compliance  with
its  obligations  under the  Policy,  the Policy is in full force and effect and
Ambac is not subject to any bankruptcy, insolvency or similar proceedings:

          (i) any provision of this Note, the Second  Supplement  Indenture,  or
     the  Indenture   (collectively,   the  "Financing   Documents")   expressly
     recognizing  or  granting  rights in or to Ambac may not be  amended in any
     manner which affects the rights of Ambac  hereunder or  thereunder  without
     the prior written consent of Ambac.

          (ii) Ambac  shall be deemed to be the owner of all  outstanding  Notes
     for all purposes (including,  without limitation, all approvals,  consents,
     requests, waivers, authorizations,  directions,  inspections,  appointments
     and the institution of any action),  provided,  that nothing in this clause
     (ii)  shall   impair   the  rights  of  the   holders  of  the  Notes  (the
     "Securityholders")  to receive all  payments  due under the Notes.  Ambac's
     consent shall be required with respect to (a) the execution and delivery of
     any supplemental indenture to the Indenture for which the consent of any of
     the Securityholders is required, or any amendment,  supplement or change to
     or modification of any Financing  Document (except as otherwise provided by
     Section  901 of the  Indenture)  and (b) the  removal of the Trustee or any
     paying agent and selection  and  appointment  of any  successor  trustee or
     paying agent.

          (iii)  Any   reorganization   or  liquidation  plan  under  applicable
     bankruptcy  law or  similar  law  with  respect  to  the  Company  must  be
     acceptable  to  Ambac.  In  the  event  of  any  such   reorganization   or
     liquidation,  Ambac  shall  have  the  right  to  vote  on  behalf  of  all
     Securityholders  who hold  Ambac-insured  Notes  absent a default  by Ambac
     under the applicable  Financial  Guaranty  Insurance  Policy  insuring such
     Notes.

          (iv)   Anything   in  any   Financing   Document   to   the   contrary
     notwithstanding,  upon  the  occurrence  and  continuance  of an  Event  of
     Default,  Ambac shall be entitled to control and direct the  enforcement of
     all rights and remedies granted to the  Securityholders  or the Trustee for
     the  benefit  of  the  Securityholders   under  the  Financing   Documents,
     including, without limitation: (A) the right to accelerate the principal of
     the Notes as  described  in the  Indenture,  and (B) the right to annul any
     declaration  of  acceleration,  and Ambac shall also be entitled to approve
     all waivers of Events of Default with respect to or effecting the Notes.




          (v) While the Financial  Guaranty  Insurance Policy is in effect,  the
     Company (and/or the Trustee,  where indicated below) shall furnish to Ambac
     (to  the  attention  of  the  Surveillance  Department,   unless  otherwise
     indicated):

               (a) as soon as practicable  after the filing  thereof,  a copy of
          any  financial  statement  of the  Company and a copy of any audit and
          annual report of the Company;

               (b) such additional information it may reasonably request;

               (c)  a  copy  of  any  notice  to  be  given  to  the  registered
          Securityholders,   including,   without  limitation,   notice  of  any
          redemption or defeasance of the Notes,  and any  certificate  rendered
          pursuant  to any  Financing  Document  relating  to the  Notes,  which
          obligation shall bind the Trustee as well as the Company;

               (d) notice  (attention:  General  Counsel)  by the Trustee of any
          failure of the Company to provide relevant notices, certificates, etc.
          under the Financing Documents; and

               (e)   notwithstanding   any  other  provision  of  any  Financing
          Document, immediate notice (attention: General Counsel) if at any time
          there are insufficient moneys to make any payments of principal and/or
          interest  on  the  Notes  as  required  and  immediate  notice  of the
          occurrence of any Event of Default,  which  obligation  shall bind the
          Trustee as well as the Company.

          (vi)  Notwithstanding  anything  herein  or  in  any  other  Financing
     Document to the contrary,  in the event that the principal  and/or interest
     due on the Notes shall be paid by Ambac pursuant to the Financial  Guaranty
     Insurance Policy, (a) the Notes shall remain "outstanding" for all purposes
     under the Indenture,  not be considered defeased or otherwise satisfied and
     not be  considered  paid by the  Company,  (b) except as  expressly  stated
     herein or otherwise  agreed or  undertaken  (I) the Paying  Agent,  if any,
     shall have no duties or obligations  relating to any payments made by Ambac
     and (II) the Trustee  shall not be deemed to have  knowledge of any default
     unless the Trustee shall have written  notice  thereof,  (c) the assignment
     and  pledge  of the  Indenture  and all  covenants,  agreements  and  other
     obligations of the Company to the  Securityholders  shall continue to exist
     and shall run to the benefit of Ambac, and (d) Ambac shall be subrogated to
     the rights of such Securityholders to the extent of each such payment.

          (vii) As long as the Financial  Guaranty  Insurance Policy shall be in
     full force and effect, the Company,  the Trustee and any Paying Agent agree
     to comply with the following provisions:

               (a) at least one (1) day prior to all Interest  Payment Dates the
          Trustee or Paying Agent, if any, will determine  whether there will be
          sufficient  funds available to pay the principal of or interest on the
          Notes on such  Interest  Payment Date. If the Trustee or Paying Agent,
          if any,  determines that there will be insufficient  funds  available,
          the  Trustee or Paying  Agent,  if any,  shall so notify  Ambac.  Such
          notice shall  specify the amount of the  anticipated  deficiency,  the
          Notes to which such  deficiency is  applicable  and whether such Notes
          will be deficient as to principal or interest, or both. If the Trustee
          or Paying  Agent,  if any, has not so notified  Ambac at least one (1)
          day prior to an Interest  Payment  Date,  Ambac will make  payments of
          principal  or  interest  due on the Notes on or before the first (1st)
          day next following the date on which Ambac shall have received  notice
          of nonpayment from the Trustee or Paying Agent, if any.

               (b) the Trustee or Paying  Agent,  if any,  shall,  after  giving
          notice to Ambac as provided in (a) above, make available to Ambac and,
          at Ambac's direction,  to The Bank of New York, in New York, New York,
          as insurance trustee for Ambac or any successor insurance trustee (the
          "Insurance Trustee"), the registration books of the Company maintained
          by the Trustee or Paying  Agent,  if any, and all records  relating to
          the funds and accounts (if any) maintained under the Indenture.

               (c) the Trustee or Paying Agent,  if any, shall provide Ambac and
          the  Insurance  Trustee  with a list of  registered  owners  of  Notes
          entitled to receive  principal or interest  payments  from Ambac under
          the  terms of the  Financial  Guaranty  Insurance  Policy,  and  shall
          pursuant to arrangements with the Insurance Trustee (I) mail checks or
          drafts to the  registered  owners of Notes entitled to receive full or
          partial interest payments from Ambac and (II) pay principal upon Notes
          surrendered to the Insurance Trustee by the registered owners of Notes
          entitled to receive full or partial principal payments from Ambac.

               (d) the Trustee or Paying Agent,  if any,  shall,  at the time it
          provides  notice to Ambac  pursuant  to (a) above,  notify  registered
          owners of Notes  entitled  to  receive  the  payment of  principal  or
          interest  thereon  from Ambac (I) as to the fact of such  entitlement,
          (II) that Ambac will remit to them,  through the Insurance  Trustee or
          pursuant to arrangements  made with the Insurance  Trustee through the
          Trustee  or  Paying  Agent,  if  any,  all or a part  of the  interest
          payments next coming due upon proof of  Securityholder  entitlement to
          interest  payments  and  delivery to the  Insurance  Trustee,  in form
          satisfactory to the Insurance Trustee, of an appropriate assignment of
          the  registered  owner's  right to payment,  (III) that should they be
          entitled to receive full payment of  principal  from Ambac,  they must
          surrender  their  Notes  (along  with  an  appropriate  instrument  of
          assignment in form  satisfactory  to the  Insurance  Trustee to permit
          ownership  of such  Notes to be  registered  in the name of Ambac) for
          payment to the Insurance Trustee, who shall then pass such Notes on to
          the Trustee or Paying  Agent,  if any, for payment of  principal  upon
          such Notes and (IV) that should  they be  entitled to receive  partial
          payment of  principal  from Ambac,  for payment of  principal  on such
          Notes they must surrender their Notes for payment thereon first to the
          Trustee  or Paying  Agent,  if any,  who shall  note on such Notes the
          portion of the principal paid by the Trustee or Paying Agent,  if any,
          and then,  along with an appropriate  instrument of assignment in form
          satisfactory to the Insurance Trustee, to the Insurance Trustee, which
          will then make  arrangements  with the Trustee or the Paying Agent, if
          any, for the payment of the unpaid portion of principal.

               (e) in the event that the Trustee or Paying  Agent,  if any,  has
          notice  that any payment of  principal  of or interest on a Note which
          has become Due for  Payment  (as  defined  in the  Financial  Guaranty
          Insurance  Policy)  and  which  is made to a  Securityholder  by or on
          behalf of the  Company  has been deemed a  preferential  transfer  and
          theretofore recovered from its registered owner pursuant to the United
          States  Bankruptcy  Code by a trustee in bankruptcy in accordance with
          the  final,   nonappealable   order  of  a  court   having   competent
          jurisdiction,  the Trustee or Paying Agent, if any, shall, at the time
          Ambac is notified pursuant to (a) above,  notify all registered owners
          that in the event that any registered owner's payment is so recovered,
          such  registered  owner will be entitled to payment  from Ambac to the
          extent  of  such  recovery  if  sufficient  funds  are  not  otherwise
          available,  and the Trustee or Paying Agent,  if any, shall furnish to
          Ambac its records evidencing the payments of principal of and interest
          on the Notes which have been made by the Trustee or Paying  Agent,  if
          any, and subsequently  recovered from registered  owners and the dates
          on which such payments were made.

               (f) in addition to those rights granted Ambac under the Financing
          Documents, Ambac shall, to the extent it makes payment of principal of
          or  interest  on  Notes,  become  subrogated  to  the  rights  of  the
          recipients  of such  payments  in  accordance  with  the  terms of the
          Financial  Guaranty Insurance Policy, and to evidence such subrogation
          (1) in the case of subrogation as to claims for past due interest, the
          Trustee or Paying Agent, if any, shall note Ambac's rights as subrogee
          on the registration  books of the Company maintained by the Trustee or
          Paying Agent,  if any, upon receipt from Ambac of proof of the payment
          of interest thereon to the registered  owners of the Notes, and (2) in
          the case of  subrogation  as to  claims  for past due  principal,  the
          Trustee or Paying Agent, if any, shall note Ambac's rights as subrogee
          on the registration  books of the Company maintained by the Trustee or
          Paying Agent,  if any, upon  surrender of the Notes by the  registered
          owners  thereof  together  with  proof  of the  payment  of  principal
          thereof.

          (viii) The  Trustee  or Paying  Agent,  if any,  may be removed at any
     time, at the request of Ambac, for any breach of its obligations  under the
     Financing Documents.

          (ix) Ambac  shall  receive  prior  written  notice of any  Trustee (or
     Paying Agent) resignation.

          (x) Every successor Trustee appointed  pursuant to the Indenture shall
     be a trust  company or bank in good  standing  located  in or  incorporated
     under  the  laws  of any  State  of the  United  States  of  America,  duly
     authorized to exercise  trust powers and subject to  examination by federal
     or state authority,  having a reported capital and surplus of not less than
     $75,000,000  and  acceptable  to Ambac.  Any  successor  Paying  Agent,  if
     applicable,  shall not be appointed unless Ambac approves such successor in
     writing.

          (xi)  Notwithstanding any other provision of the Financing  Documents,
     in determining whether the rights of the Securityholders  will be adversely
     affected by any action taken  pursuant to the terms and  provisions  of the
     Financing  Documents,  the Trustee (or Paying  Agent)  shall  consider  the
     effect  on the  Securityholders  as if  there  were no  Financial  Guaranty
     Insurance Policy.

          (xii)  Notwithstanding any other provision of the Financing Documents,
     no removal,  resignation  or  termination  of the Trustee (or Paying Agent)
     shall  take  effect  until a  successor,  acceptable  to  Ambac,  shall  be
     appointed.

          (xiii) To the extent that the Financing  Documents confer upon or give
     or grant to Ambac  any  right,  remedy  or claim  thereunder  or by  reason
     thereof,  Ambac is  hereby  explicitly  recognized  as being a  third-party
     beneficiary  thereunder  and may  enforce  any such  right  remedy or claim
     conferred, given or granted thereunder.

          (xiv) Nothing in the  Financing  Documents,  expressed or implied,  is
     intended or shall be construed to confer upon,  or to give or grant to, any
     person or entity,  other than the Company,  the Trustee,  Ambac, the Paying
     Agent,  if any, and the registered  Securityholders,  any right,  remedy or
     claim  under or by  reason  of the  Financing  Documents  or any  covenant,
     condition or stipulation thereof, and all covenants, stipulations, promises
     and agreements in the Financing Documents contained by and on behalf of the
     Company  shall be for the sole and  exclusive  benefit of the Company,  the
     Trustee,   Ambac,   the  Paying   Agent,   if  any,   and  the   registered
     Securityholders.

          (xv) The  Company  may not  elect  to  defease  the  Series B Notes in
     accordance  with Section 401, 403 or 1009 of the Indenture  without  having
     obtained  the prior  written  consent  of  Ambac,  such  consent  not to be
     unreasonably  withheld. No such defeasance shall be effected by the deposit
     or delivery of U.S.  Government  Obligations  with or to the Trustee unless
     the securities or instruments  used for such purpose would constitute "U.S.
     Government Obligations" under clause (i) of the definition of such term.

     It shall be an Event  of  Default  under  the  Indenture  if an  "Event  of
Default"  shall have occurred and be continuing  under the Insurance  Agreement,
dated as of November 26, 2002, between the Company and Ambac. If Ambac waives an
Event of  Default  under the  Insurance  Agreement  or such  Event of Default is
cured,  then such Event of Default  will not be an Event of Default with respect
to the Senior Notes under the Indenture.

     The Company  shall not be required to (i) issue,  exchange or register  the
transfer of any Notes  during a period  beginning  at the opening of business 15
days  before the day of the mailing of a notice of  redemption  of less than all
the outstanding  Notes of the same series and ending at the close of business on
the day of such  mailing,  nor (ii)  register the transfer of or exchange of any
Notes of any series or portions thereof called for redemption.  This Global Note
is  exchangeable  for Notes in  definitive  registered  form only under  certain
limited circumstances set forth in the Indenture.






     In the event of  redemption  of this Note in part only, a new Note or Notes
of this series, of like tenor, for the unredeemed  portion hereof will be issued
in the name of the Holder hereof upon the surrender of this Note.

     In case an Event of  Default,  as  defined  in the  Indenture,  shall  have
occurred and be  continuing,  the principal of all of the Notes may be declared,
and upon such declaration shall become, due and payable, in the manner, with the
effect and subject to the conditions provided in the Indenture.

     The Indenture contains  provisions for defeasance at any time of the entire
indebtedness of this Note upon compliance by the Company with certain conditions
set forth therein.

     The Indenture contains  provisions  permitting the Company and the Trustee,
with the  consent  of the  Holders  of not less  than a  majority  in  aggregate
principal  amount of the Notes of each series affected at the time  outstanding,
as defined in the Indenture,  to execute supplemental indentures for the purpose
of adding any provisions to or changing in any manner or eliminating  any of the
provisions of the Indenture or of any supplemental  indenture or of modifying in
any manner the rights of the Holders of the Notes;  provided,  however,  that no
such supplemental  indenture shall (i) extend the fixed maturity of any Notes of
any series, or reduce the principal amount thereof, or reduce the rate or extend
the time of payment of interest thereon,  or reduce any premium payable upon the
redemption thereof, or reduce the amount of the principal of a Discount Security
that would be due and payable upon a declaration of acceleration of the maturity
thereof  pursuant  to the  Indenture,  without the consent of the holder of each
Note then  outstanding  and affected;  (ii) reduce the  aforesaid  percentage of
Notes,  the holders of which are  required  to consent to any such  supplemental
indenture,  or reduce the percentage of Notes, the holders of which are required
to waive any default and its consequences,  without the consent of the holder of
each Note then outstanding and affected  thereby;  or (iii) modify any provision
of Section 502 of the Indenture  (except to increase the percentage of principal
amount of securities  required to rescind and annul any  declaration  of amounts
due and payable under the Notes), without the consent of the holder of each Note
then outstanding and affected  thereby.  The Indenture also contains  provisions
permitting the Holders of a majority in aggregate  principal amount of the Notes
of all series at the time outstanding affected thereby, on behalf of the Holders
of the Notes of such series, to waive any past default in the performance of any
of the covenants  contained in the  Indenture,  or  established  pursuant to the
Indenture with respect to such series, and its consequences, except a default in
the payment of the  principal  of or premium,  if any, or interest on any of the
Notes of such  series.  Any such consent or waiver by the  registered  Holder of
this Note (unless revoked as provided in the Indenture)  shall be conclusive and
binding upon such Holder and upon all future Holders and owners of this Note and
of  any  Note  issued  in  exchange  herefor  or in  place  hereof  (whether  by
registration  of  transfer  or  otherwise),  irrespective  of whether or not any
notation of such consent or waiver is made upon this Note.

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

     As provided in the Indenture and subject to certain limitations therein set
forth, this Note is transferable by the registered holder hereof on the Security
Register  of the  Company,  upon  surrender  of this  Note for  registration  of
transfer  at the  office or agency of the  Company as may be  designated  by the
Company  accompanied by a written  instrument or instruments of transfer in form
satisfactory  to the Company or the  Trustee  duly  executed  by the  registered
Holder hereof or his or her attorney duly  authorized in writing,  and thereupon
one or more new Notes of  authorized  denominations  and for the same  aggregate
principal  amount  and series  will be issued to the  designated  transferee  or
transferees.  No  service  charge  will be made for any such  transfer,  but the
Company  may  require  payment  of a sum  sufficient  to cover  any tax or other
governmental charge payable in relation thereto.

     Prior to due  presentment  for  registration  of transfer of this Note, the
Company,  the Trustee,  any paying agent and any Security Registrar may deem and
treat the registered  Holder hereof as the absolute owner hereof (whether or not
this Note shall be  overdue  and  notwithstanding  any  notice of  ownership  or
writing hereon made by anyone other than the Security Registrar) for the purpose
of receiving  payment of or on account of the principal  hereof and premium,  if
any, and interest due hereon and for all other purposes, and neither the Company
nor the  Trustee  nor any  paying  agent  nor any  Security  Registrar  shall be
affected by any notice to the contrary.

     No  recourse  shall  be had  for the  payment  of the  principal  of or the
interest on this Note,  or for any claim based  hereon,  or otherwise in respect
hereof,  or based on or in respect of the Indenture,  against any  incorporator,
stockholder,  officer or  director,  past,  present or future,  as such,  of the
Company or of any predecessor or successor corporation, 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.

     The Notes of this  series are  issuable  only in  registered  form  without
coupons in denominations of $25 and any integral multiple  thereof.  As provided
in the  Indenture and subject to certain  limitations,  Notes of this series are
exchangeable for a like aggregate  principal amount of Notes of this series of a
different authorized  denomination,  as requested by the Holder surrendering the
same.

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

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]







     This  Note  shall  not be  entitled  to any  benefit  under  the  Indenture
hereinafter referred to, be valid or become obligatory for any purpose until the
Certificate of  Authentication  hereon shall have been signed by or on behalf of
the Trustee.

     IN WITNESS WHEREOF, the Company has caused this Instrument to be executed.

                                            PUBLIC SERVICE COMPANY OF OKLAHOMA


                                            By:___________________________
                                                     Assistant Treasurer

Attest:


By:___________________________
       Assistant Secretary


                          CERTIFICATE OF AUTHENTICATION

     This is one of the Notes of the series of Notes  designated  in  accordance
with, and referred to in, the within-mentioned Indenture.

Dated:  November 26, 2002

THE BANK OF NEW YORK, as Trustee


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)

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

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

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






                                                                   EXHIBIT 5(a)






                                                              November 26, 2002


Public Service Company of Oklahoma
1 Riverside Plaza
Columbus, Ohio 43215

Ladies and Gentlemen:

          We have acted as counsel to Public  Service  Company of  Oklahoma,  an
Oklahoma  corporation  (the  "Company"),  in  connection  with the  Registration
Statement on Form S-3 (Registration Statement No. 333-100623) (the "Registration
Statement")  filed by the Company with the  Securities  and Exchange  Commission
(the  "Commission")  under the  Securities  Act of 1933, as amended (the "Act"),
relating to $200,000,000  aggregate  principal amount of Senior Notes, Series B,
due 2032 (the "Senior Notes") issued under an Indenture, dated as of November 1,
2000 (the "Indenture"), between the Company and The Bank of New York, as Trustee
(the "Trustee").

          We have examined the  Registration  Statement and the Indenture  which
has been filed with the Commission as an exhibit to the Registration  Statement.
We also have  examined the  originals,  or  duplicates or certified or conformed
copies,  of such records,  agreements,  instruments and other documents and have
made such  other and  further  investigations  as we have  deemed  relevant  and
necessary in connection with the opinions  expressed  herein. As to questions of
fact  material  to this  opinion,  we have relied  upon  certificates  of public
officials and of officers and representatives of the Company.

          In  rendering  the  opinions  set forth  below,  we have  assumed  the
genuineness  of all  signatures,  the legal  capacity  of natural  persons,  the
authenticity  of all documents  submitted to us as originals,  the conformity to
original  documents of all documents  submitted to us as duplicates or certified
or  conformed  copies,  and the  authenticity  of the  originals  of such latter
documents. We also have assumed that: (1) the Indenture is the valid and legally
binding obligation of the Trustee; and (2) the Company is validly existing under
the laws of Oklahoma.

          We have  assumed  further  that (1) the Company  has duly  authorized,
executed and delivered the Indenture and (2) execution, delivery and performance
by the Company of Indenture and the Unsecured  Notes do not and will not violate
the laws of Oklahoma or any other  applicable  laws  (excepting  the laws of the
State of New York and the Federal laws of the United States).

          Based  upon the  foregoing,  and  subject  to the  qualifications  and
limitations  stated  herein,  we  are of  the  opinion  that  assuming  the  due
authentication  of the Senior Notes by the Trustee,  the Senior Notes constitute
valid and legally  binding  obligations of the Company  enforceable  against the
Company  in  accordance  with  their  terms,  subject  to  the  effects  of  (i)
bankruptcy,  insolvency, fraudulent conveyance,  reorganization,  moratorium and
other similar laws relating to or affecting  creditors' rights  generally,  (ii)
general equitable principles (whether considered in a proceeding in equity or at
law) and (iii) an implied covenant of good faith and fair dealing.

          We are  members  of the Bar of the  State of New  York,  and we do not
express any opinion herein concerning any law other than the law of the State of
New York and the Federal law of the United States.

          We hereby consent to the filing of this opinion letter as Exhibit 5(a)
to the  Registration  Statement  and to the use of our name  under  the  caption
"Legal Opinions" in the Prospectus included in the Registration Statement.

                                              Very truly yours,

                                              /s/ Simpson Thacher & Bartlett

                                              SIMPSON THACHER & BARTLETT






                                                                    EXHIBIT 23

                          INDEPENDENT AUDITORS' CONSENT


The Board of Directors
Ambac Assurance Corporation:

     We consent to the incorporation by reference in the registration  statement
(No.  333-100623) of Public Service Company of Oklahoma (the "Registrant"),  and
in the Prospectus  Supplement of the Registrant (the  "Prospectus  Supplement"),
via the Form 8-K of the  Registrant  dated November 21, 2002 of our report dated
January 23, 2002 on the  consolidated  financial  statements of Ambac  Assurance
Corporation  and  subsidiaries as of December 31, 2001 and 2000, and for each of
the years in the three-year period ended December 31, 2001, which report appears
in the Annual Report on Form 10-K of Ambac Financial Group, Inc. which was filed
with  the  Securities  and  Exchange  Commission  on March  26,  2002 and to the
reference to our firm under the heading "Experts" in the Prospectus Supplement.

/s/ KPMG LLP

New York, New York
November 26, 2002