PUBLIC SERVICE COMPANY OF OKLAHOMA Underwriting Agreement Dated November 8, 2007

(a)

That all legal proceedings to be taken and all legal opinions to be rendered in connection with the issue and sale of the Notes shall be satisfac­tory in form and substance to Dewey & LeBoeuf 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 & LeBoeuf LLP, counsel to the Underwriters

(1)

Opinion of Jeffrey D. Cross, Esq. or Thomas G. Berkemeyer, Esq., counsel to the Company, substantially in the form heretofore previously provided to the Underwriters; and

(2)

Opinion of Dewey & LeBoeuf LLP, counsel to the Underwriters, substantially in the form heretofore previously provided to the Underwriters.

(c)

That the Representative shall have received on the date hereof and shall receive at the Time of Purchase letters from Deloitte & Touche LLP dated the date hereof and the date of the Time of Purchase, respectively, in form and substance satisfactory to the Representative (which may refer to the letter previously delivered to the Representative, as applicable) (i) confirming that with respect to the Company they are an independent registered public accounting firm within the meaning of the Act and the applicable published rules and regulations of the Commission and the Public Company Accounting Oversight Board (United States) thereunder, (ii) stating that in their opinion the financial statements audited by them and included or incorporated by reference in the Registration Statement, Pricing Prospectus and Prospectus, respectively, 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 less than three business days prior to the date of each such letter, as applicable, such other matters as the Representative reasonably requests.

(d)

The pricing term sheet contemplated by Section 6(b) hereof, and any other material required pursuant to Section 433(d), shall have been filed by the Company with the Commission within the applicable time periods prescribed by Rule 433.

(e)

That no amendment to the Registration Statement and that no supplement to the Pricing Prospectus or the Prospectus of the Company (other than the Pricing Prospectus or amendments, prospectuses or prospectus supplements relating solely to securities other than the Notes) relating to the Notes and no document which would be deemed incorporated in the Pricing Prospectus or 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 Pricing Prospectus which is unsatisfactory in substance to the Representative or unsatisfactory in form to Dewey & LeBoeuf LLP, counsel to the Underwriters.

(f)

That, at the Time of Purchase, an appropriate order of the Corporation Commission of the State of Oklahoma, necessary to permit the sale of the 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.

(g)

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 Pricing Prospectus (other than changes referred to in or contemplated by the Pricing 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.

(j)

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.

(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 and make any other required filings pursuant to Rule 433; 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, Pricing Prospectus or Prospectus or for additional information with respect thereto or of the entry of an order suspending the effectiveness of the Registration Statement or preventing or suspending the use of the Pricing Prospectus or the Prospectus or of the initiation or threat of any proceedings for that purpose and, if such an 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 (or required to deliver but for Rule 172 under the Act), 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 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 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 (or required to deliver but for Rule 172 under the Act), if any event shall have occurred as a result of which it is necessary to amend or supplement the Pricing Prospectus or the Prospectus in order to make the statements therein, in the light of the circumstances when the Pricing Prospectus or 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 will be furnished to the Company by the Representative) to whom principal amounts of the 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 Pricing Prospectus or the Prospectus or supplements to the Pricing Prospectus or 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 Notes for offer and sale under the securities or “blue sky” laws of such jurisdictions as the Representative may designate and shall maintain such qualifications so long as required for the offering and sale of the Notes 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 Notes by the respective Underwriters) in connection with the issuance and delivery of the Notes, except 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 counsel to the Underwriters, only in the events provided in paragraph (h) of this Section 4 and paragraph (a) of Section 8, 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 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 9 or 10 hereof, to pay the fees and disbursements of counsel to the Underwriters, and, if the Underwriters shall not take up and pay for the 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)

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 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 Notes of the Company or any substantially similar securities of the Company without the consent of the Representative.

(a)

the Registration Statement on its effective date complied with the applicable provisions of the Act and the rules and regulations of the Commission and the Registration Statement at its effective date and as of the Applicable Time 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, the Pricing Disclosure Package as of the Applicable Time did not contain an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading, and the Basic Prospectus on the date of this Agreement and the Prospectus as of its date 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 (Trust Indenture Act), and the rules and regulations of the Commission, the Basic Prospectus and the Prospectus as of their respective dates 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, any Permitted Free Writing 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 the Trustee under the Indenture.

(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 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 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 Pricing Prospectus, when they were filed with the Commission, complied in all material respects with the applicable provisions of the Securities Exchange Act of 1934, as amended and the rules and regulations of the Commission thereunder, and as of such time of filing, when read together with the Pricing Prospectus, the Permitted Free Writing Prospectuses and 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.  The information contained in a Permitted Free Writing Prospectus listed in Exhibit 3 does not conflict with the information contained in the Registration Statement, the Pricing Prospectus or the Prospectus and no such Permitted Free Writing Prospectus, taken together with the remainder of the Pricing Disclosure Package as of the Applicable Time, did contain an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in 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 Pricing 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 Notes or the consummation of 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) the qualification of the Indenture under the Trust Indenture Act; (C) the approval of the Corporation Commission of the State of Oklahoma; and (D) 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 Pricing Prospectus and 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 Pricing Prospectus and the Prospectus presents fairly the information shown therein and has 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 Pricing Prospectus and 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 Pricing Prospectus.

(j)

At the determination date for purposes of the Notes within the meaning of Rule 164(h) under the Act, the Company was not an “ineligible issuer” as defined in Rule 405 under the Act.

(k)

The Company has not made any filings pursuant to the Securities Exchange Act of 1934, as amended, or the rules and regulations thereunder, within 24 hours preceding the Applicable Time.

6.  

Free Writing Prospectuses:

(a)

The Company represents and agrees that, without the prior consent of the Representative, it has not made and will not make any offer relating to the Notes that would constitute a “free writing prospectus” as defined in Rule 405 under the Act, other than a Permitted Free Writing Prospectus; each Underwriter, severally and not jointly, represents and agrees that, without the prior consent of the Company and the Representative, it has not made and will not make any offer relating to the Notes that would constitute a “free writing prospectus,” as defined in Rule 405 under the Act, other than a Permitted Free Writing Prospectus or one or more free writing prospectuses that contain only preliminary or final terms of the Notes (which may include prices of bonds from comparable issuers) and is not required to be filed by the Company pursuant to Rule 433 or one or more free writing prospectuses that contains information substantially the same as the information contained in Exhibit 2 hereto (an “Underwriter Free Writing Prospectus”); any such free writing prospectus the use of which has been consented to by the Company and the Representative (which shall include the pricing term sheet discussed in Section 6(b)) is listed in Exhibit 3 and herein called a “Permitted Free Writing Prospectus.”

(b)

The Company agrees to prepare a pricing term sheet, substantially in the form of Exhibit 2 hereto and approved by the Representative, and to file such pricing term sheet pursuant to Rule 433(d) under the Securities Act within the time period prescribed by such Rule.

(c)

The Company and each Underwriter has complied and will comply with the requirements of Rule 433 applicable to any other Permitted Free Writing Prospectus, including timely Commission filing where required and legending.

(d)

The Company and each Underwriter agrees that if at any time following issuance of a Permitted Free Writing Prospectus any event occurred or occurs as a result of which such Permitted Free Writing Prospectus would conflict in any material respect with the information in the Registration Statement, the Pricing Prospectus or the Prospectus or include an untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in light of the circumstances then prevailing, not misleading, then (i) the party that first becomes aware of the foregoing will give prompt notice thereof to the Representative and/ or the Company, as applicable, and, (ii) if requested by the Representative or the Company, as applicable, the Company will prepare and furnish without charge a Permitted Free Writing Prospectus or other document which will correct such conflict, statement or omission.

(e)

Each Underwriter agrees that (i) no information that is conveyed to investors by such Underwriter has been or will be inconsistent with the information contained in the Pricing Disclosure Package, and (ii) if an Underwriter shall use an Underwriter Free Writing Prospectus that contains information in addition to, or in conflict with, the Pricing Disclosure Package, the liability arising from its use of such additional or conflicting information shall be the sole responsibility of the Underwriter using such Underwriter Free Writing Prospectus; provided, however, that, for the avoidance of doubt, this clause 6(e)(ii) shall not be interpreted as tantamount to the indemnification obligations contained in Section 8(b) hereof.

 

(a)

To the extent permitted by law, the Company agrees to indemnify and hold each Underwriter harmless, each Underwriter’s employees, agents, officers and directors and each person, if any, who controls an Underwriter within the meaning of Section 15 of the Act, against any and all losses, claims, damages or liabilities, joint or several, to which an Underwriter, they or any of you or them may become subject under the Act or otherwise, and to reimburse the Underwriters, they or any of you or them, 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), in the Pricing Prospectus, in any Permitted Free Writing Prospectus, in any “issuer free writing prospectus” (as defined in Rule 433 under the Act) or in the Prospectus, or if the Company shall furnish or cause to be furnished to the Underwriters any amendments or any supplements to the Pricing Prospectus or the Prospectus, in the Pricing Prospectus or the Prospectus as so amended or supplemented except to the extent that such amendments or supplements relate solely to securities other than the 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, in the Pricing Prospectus, in any Permitted Free Writing Prospectus, in any “issuer free writing prospectus” (as defined in Rule 433 under the Act) 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 the Trustee under the Indenture.  Each Underwriter agrees promptly after its receipt 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 8(a) may be sought by any such Underwriter, or by any person controlling any such Underwriter, to notify the Company in writing of the commencement thereof, but the omission so to notify the Company of any such action shall not release the Company from any liability which it may have to an Underwriter or to such controlling person otherwise than on account of the indemnity agreement contained in this Section 8(a).  In case any such action shall be brought against an Underwriter or any such controlling person and an Underwriter 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), an Underwriter or any controlling person shall have the right to employ its own counsel, but, in any such case, the fees and expenses of such counsel shall be at such Underwriter’s or controlling person’s 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 an Underwriter or any controlling person and the Company and such Underwriter or any controlling person shall have been advised by its counsel that a conflict of interest between the Company and such Underwriter 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 the Underwriters or any controlling person (plus any local counsel retained by the Underwriters or any controlling person in their reasonable judgment), which firm (or firms) shall be designated in writing by the Underwriters 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 8(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 (if used prior to the effective date of this Agreement), or in the Pricing Prospectus, or in any Permitted Free Writing 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 8(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 8(b).

(c)

If recovery is not available or insufficient to hold the indemnified party harmless under Section 8(a) or 8(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 8(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 Notes realized by the Company on the one hand and the Underwriters on the other hand, 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 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 8 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 indemnification or contribution could be sought under this Section 8 (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.

(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 further downgrade.

Name

Principal Amount of Series G Notes

Citigroup Global Markets Inc.

           $  62,500,000

Merrill Lynch, Pierce, Fenner & Smith

                     Incorporated

 

    62,500,000

Morgan Stanley & Co. Incorporated

    62,500,000

UBS Securities LLC

    62,500,000

TOTAL

$250,000,000

Issuer:

Public Service Company of Oklahoma

Designation:

Senior Notes, Series G, due 2037

Principal Amount:

$250,000,000

Maturity:

November 15, 2037

Coupon

6.625%

Interest Payment Dates:

May 15 and November 15

First Interest Payment Date:

May 15, 2008

Treasury Benchmark:

4.750% due February 15, 2037

Treasury Price:

101-2

Treasury Yield:

4.683%

Reoffer Spread:

2.000%

Yield to Maturity:

6.683%

Price to Public:

99.253% of the principal amount thereof

Transaction Date:

November 8, 2007

Settlement Date:

November 14, 2007 (T+3)

Redemption Terms:

At any time at a discount rate of the Treasury Rate plus 30 basis points

Minimum Denomination:

$1,000

CUSIP:

744533 BJ8

Joint Book-Running Managers:

Citigroup Global Markets Inc.

Merrill Lynch, Pierce, Fenner & Smith

                     Incorporated

Morgan Stanley & Co. Incorporated

UBS Securities LLC

Ratings:

Baa1 by Moody’s Investors Service, Inc.

BBB by Standard & Poor’s Ratings Services

A- by Fitch Ratings Ltd.

1)

Prospectus dated May 4, 2006

2)

Preliminary Prospectus Supplement dated November 8, 2007 (including Incorporated Documents)

3)

Permitted Free Writing Prospectuses

a)           Pricing Term Sheet attached as Exhibit 2 hereto