PUBLIC SERVICE COMPANY OF COLORADO

                                  $575,000,000

    $300,000,000 4.375% First Collateral Trust Bonds, Series No. 14, due 2008
    $275,000,000 5.50% First Collateral Trust Bonds, Series No. 15, due 2014

                             UNDERWRITING AGREEMENT

                                                              New York, New York
                                                               September 2, 2003

Banc One Capital Markets, Inc.
1 Bank One Plaza
Chicago, Illinois 60670

McDonald Investments Inc.
800 Superior Avenue
Cleveland, Ohio 44114

UBS Securities LLC
677 Washington Boulevard
Stamford, Connecticut 06901

As Representatives of the several Underwriters

Ladies and Gentlemen:

         Public Service Company of Colorado, a corporation organized under the
laws of the State of Colorado (the "Company"), proposes to issue and sell to the
several parties named in Schedule I hereto (the "Underwriters"), for whom you
(the "Representatives") are acting as representatives, $300,000,000 principal
amount of the Company's 4.375% First Collateral Trust Bonds, Series No. 14, due
2008 and $275,000,000 principal amount of the Company's 5.50% First Collateral
Trust Bonds, Series No. 15, due 2014 (collectively, the "Bonds"). The Bonds are
to be issued under the Company's Indenture, dated as of October 1, 1993 (the
"Original Indenture") to U.S. Bank Trust National Association, as successor
trustee (the "Trustee"), as heretofore supplemented and as it will be further
supplemented by a supplemental indenture creating the Bonds (said Original
Indenture, as so supplemented and to be further supplemented, and said
supplemental indenture being hereafter referred to as the "Indenture" and the
"Supplemental Indenture", respectively). Certain terms used herein are defined
in Section 16 hereof.

         1.       Representations and Warranties. The Company represents and
warrants to, and agrees with, each Underwriter that:

                  (a)      (i) A registration statement on Form S-3 (File No.
         333-104504) in respect of the Bonds and certain other securities has
         been prepared and filed with the Commission in accordance with the
         provisions of the Act; such registration statement and any
         post-effective



         amendment thereto have been declared effective by the Commission; such
         registration statement in the form in which it became effective and
         (including the exhibits thereto, but excluding the Statements of
         Eligibility in Form T-1) is hereinafter called the "Registration
         Statement"; and the prospectus relating to the Bonds, in the form in
         which it was included in the Registration Statement at the time it
         became effective, as supplemented by the prospectus supplement
         containing the terms of the Bonds and the terms of the offering
         thereof, in the form in which it is first filed with the Commission
         pursuant to Rule 424(b) under the Act, is hereinafter called the
         "Prospectus";

                           (ii)     Pursuant to Rule 429 under the Act, the
         Prospectus will be used as a combined prospectus relating to the
         Registration Statement and to the registration statement filed by the
         Company with the Commission on June 29, 1999 (registration no.
         333-81791) which became effective on July 6, 1999; unless the context
         otherwise requires, all references in this Agreement to the
         Registration Statement shall be deemed to include such prior
         registration statement;

                           (iii)    Any reference herein to the Registration
         Statement, any preliminary prospectus or the Prospectus shall be deemed
         to refer to and include the documents incorporated by reference therein
         pursuant to Item 12 of Form S-3 under the Act, as of the effective date
         for purposes of the Registration Statement or the date thereof for
         purposes of any preliminary prospectus or the Prospectus; any reference
         to any amendment to the Registration Statement shall be deemed to refer
         to and include any annual report of the Company filed pursuant to
         Section 13(a) or 15(d) of the Exchange Act after the effective date of
         the Registration Statement that is incorporated by reference in the
         Registration Statement; and any reference to any amendment or
         supplement to any preliminary prospectus or the Prospectus shall be
         deemed to refer to and include any documents filed after the date of
         such preliminary prospectus or Prospectus, under the Exchange Act, and
         incorporated by reference in such preliminary prospectus or Prospectus.

                  (b)      No stop order suspending the effectiveness of the
         Registration Statement has been issued and no proceeding for that
         purpose has been initiated or, to the best knowledge of the Company,
         threatened by the Commission and no order preventing or suspending the
         use of any preliminary prospectus or the Prospectus has been issued by
         the Commission;

                  (c)      The Registration Statement, when it became effective,
         conformed, and any further amendments thereto, when they become
         effective, will conform, in all material respects to the requirements
         of the Act and the Trust Indenture Act, and the Prospectus and any
         amendments or supplements thereto, when filed with the Commission, will
         conform in all material respects to the requirements of the Act and the
         Trust Indenture Act;

                  (d)      The Registration Statement, when it became effective,
         and any further amendments thereto when they become effective, did not
         and will not contain an 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 Prospectus and any
         amendments and supplements thereto, when they are filed or transmitted
         for filing with the Commission and at the Closing Date, will not
         include an untrue statement of a material fact or omit to state a
         material fact necessary in order to make the statements made, in light
         of the

                                        2


         circumstances under which they were made, not misleading; provided,
         however, that the representations and warranties contained in this
         subsection (d) shall not apply to statements or omissions made in
         reliance upon and in conformity with information furnished in writing
         by an Underwriter through the Representatives expressly for use in the
         Registration Statement, the Prospectus or any amendment or supplement
         to either thereof;

                  (e)      The documents incorporated by reference in the
         Registration Statement or Prospectus, when they were filed with the
         Commission, and any further documents so filed and incorporated by
         reference, when they are filed with the Commission or become effective,
         as the case may be, complied with and will comply in all material
         respects with the requirements of the Exchange Act or the Act, as the
         case may be;

                  (f)      The Company is not, and after giving effect to the
         offering and sale of the Bonds and the application of the proceeds
         thereof as described in the Prospectus will not be, an "investment
         company" or an entity "controlled" by an "investment company" within
         the meaning of the Investment Company Act of 1940, as amended, without
         taking account of any exemption arising out of the number of holders of
         the Company's securities;

                  (g)      The Company is subject to and in full compliance with
         the reporting requirements of Section 13 or Section 15(d) of the
         Exchange Act;

                  (h)      The statements in the Prospectus under the headings
         "Supplemental Description of the First Collateral Trust Bonds,"
         "Description of the First Collateral Trust Bonds," and "Description of
         the 1939 Mortgage" fairly summarize the matters therein described;

                  (i)      This Agreement has been duly authorized, executed and
         delivered by the Company;

                  (j)      The Indenture has been duly authorized and the
         Indenture (excluding the Supplemental Indenture) has been duly executed
         and delivered by the Company and is in due and proper form and
         (assuming the Indenture has been duly authorized, executed and
         delivered by the Trustee) when the Supplemental Indenture is duly
         executed and delivered the Indenture will constitute a legal, valid and
         binding mortgage of the Company, enforceable in accordance with its
         terms, except as enforcement thereof may be limited by laws and
         principles of equity affecting generally the enforcement of mortgagees'
         and other creditors' rights, including, without limitation, bankruptcy
         and insolvency laws and state laws which affect the enforcement of
         certain remedial provisions of the Indenture; provided, however, that
         such state laws will not render the remedies afforded by the Indenture
         inadequate for the practical realization of the benefit of the security
         provided thereby;

                  (k)      The issuance and sale by the Company of the Bonds
         pursuant to this Agreement have been duly authorized by all necessary
         corporate action; and, when issued, authenticated and delivered to the
         Underwriters pursuant to this Agreement against payment of the
         consideration therefor specified herein, the Bonds will be valid and
         binding obligations of the Company, enforceable in accordance with
         their terms, except as enforcement thereof may be limited by laws or
         principles of equity affecting generally the enforcement of mortgagees'
         and other creditors' rights, including, without limitation, bankruptcy
         and

                                        3


         insolvency laws and state laws which affect the enforcement of certain
         remedial provisions of the Indenture, and will be entitled to the
         benefits of the Indenture;

                  (l)      The PSCO 1939 Mortgage (as defined in the Indenture)
         has been duly authorized and the PSCO 1939 Mortgage (excluding the
         Mortgage Supplement) has been duly executed and delivered by the
         Company and is in due and proper form and (assuming the PSCO 1939
         Mortgage has been duly authorized, executed and delivered by the
         trustee thereunder) when the Mortgage Supplement is duly executed and
         delivered the PSCO 1939 Mortgage will constitute a legal, valid and
         binding mortgage of the Company, enforceable in accordance with its
         terms, except as enforcement thereof may be limited by laws and
         principles of equity affecting generally the enforcement of mortgagees'
         and other creditors' rights, including, without limitation, bankruptcy
         and insolvency laws and state laws which affect the enforcement of
         certain remedial provisions of the PSCO 1939 Mortgage; provided,
         however, that such state laws will not render the remedies afforded by
         the PSCO 1939 Mortgage inadequate for the practical realization of the
         benefit of the security provided thereby;

                  (m)      The issuance and delivery by the Company of the Class
         A Bonds (as defined in the Indenture) to be made the basis of the
         authentication and delivery of the Bonds (the "Class A Bonds") have
         been duly authorized by all necessary corporate action; and when (i)
         the Class A Bonds have been issued, authenticated and delivered to the
         Trustee pursuant to the Indenture and (ii) the Bonds have been issued,
         authenticated and delivered to the Underwriters pursuant to this
         Agreement against payment of the consideration therefor specified
         herein, the Class A Bonds will be valid and binding obligations of the
         Company, enforceable in accordance with their terms, except as
         enforcement thereof may be limited by laws or principles of equity
         affecting generally the enforcement of mortgagees' and other creditors'
         rights, including, without limitation, bankruptcy and insolvency laws
         and state laws which affect the enforcement of certain remedial
         provisions of the PSCO 1939 Mortgage, and will be entitled to the
         benefits of the PSCO 1939 Mortgage;

                  (n)      The issuance and sale of the Bonds, and the issuance
         and delivery of the Class A Bonds, have been duly authorized and
         approved by an order of The Public Utilities Commission of the State of
         Colorado and such order is final and in full force and effect on the
         date hereof, the time for appeal therefrom or review thereof or
         intervention with respect thereto having expired; no further approval,
         authorization, consent or other order of any public board or body is
         legally required in connection with the transactions contemplated by
         this Agreement, the Indenture or the PSCO 1939 Mortgage, except for the
         registration under the Act of the Bonds and as may be required under
         the blue sky laws of any jurisdiction in connection with the purchase
         and distribution of the Bonds by the Underwriters in the manner
         contemplated herein and in the Prospectus;

                  (o)      Neither the execution and delivery of this Agreement
         or the Supplemental Indenture, the issue and sale of the Bonds, nor the
         consummation of any other of the transactions herein or therein
         contemplated, nor the fulfillment of the terms hereof or thereof will
         conflict with, result in a breach or violation or imposition of any
         lien, charge or encumbrance upon any property or assets of the Company
         or any of its subsidiaries, other than the liens and security interests
         created by the Indenture and the PSCo 1939 Mortgage, pursuant to, (i)
         the charter or by-laws of the Company or any of its subsidiaries; (ii)
         the terms of any indenture, contract, lease, mortgage, deed of trust,
         note agreement, loan agreement or

                                        4


         other agreement, obligation, condition, covenant or instrument to which
         the Company or any of its subsidiaries is a party or bound or to which
         its or their property is subject; or (iii) any statute, law, rule,
         regulation, judgment, order or decree applicable to the Company or any
         of its subsidiaries of any court, regulatory body, administrative
         agency, governmental body, arbitrator or other authority having
         jurisdiction over the Company or any of its subsidiaries or any of its
         or their properties except, in the case of clause (ii), any such
         conflict, breach or violation which would not, individually or in the
         aggregate, have a material adverse change in the condition (financial
         or otherwise), prospects, earnings, business or properties of the
         Company and its subsidiaries taken as a whole, whether or not arising
         from transactions in the ordinary course of business;

                  (p)      The Company has good title to the properties
         specifically or generally described or referred to in the Indenture and
         in the PSCO 1939 Mortgage as subject to the respective liens thereof
         (except such property as may have been sold, exchanged or otherwise
         disposed of) subject only to (a) in the case of all such properties,
         the lien of the PSCO 1939 Mortgage and "permitted encumbrances" (as
         defined in the PSCO 1939 Mortgage) and (b) in the case of such
         properties which are used or to be used in or in connection with the
         Electric Utility Business (as defined in the Indenture) (whether or not
         such is the sole use of such property) the lien of the Indenture and
         Permitted Liens (as defined in the Indenture);

                  (q)      The Indenture constitutes a mortgage lien on the
         properties specifically or generally described or referred to therein
         as subject to the lien thereof (except such properties as may have been
         sold, exchanged or otherwise disposed of or released from the lien
         thereof in accordance with the terms thereof), subject to no liens
         prior to the lien of the Indenture other than Permitted Liens and the
         lien of the PSCO 1939 Mortgage; and the Indenture by its terms
         effectively subjects to the lien thereof all property (except property
         of the kinds specifically excepted from the lien of the Indenture)
         acquired by the Company after the date of execution and delivery of the
         Indenture and used or to be used in or in connection with the Electric
         Utility Business, subject to Permitted Liens, the lien of the PSCO 1939
         Mortgage, any lien thereon existing at the time of such acquisition and
         to any liens for unpaid portions of the purchase money placed thereon
         at the time of such acquisition, and also subject to the provisions of
         Article Thirteen of the Indenture and to certain possible claims of a
         trustee in bankruptcy and possible claims and taxes of the federal
         government;

                  (r)      The PSCO 1939 Mortgage constitutes a first mortgage
         lien on the properties specifically or generally described or referred
         to therein as subject to the lien thereof, including the shares of
         stock pledged thereunder (except such property as may have been sold,
         exchanged or otherwise disposed of or released from the lien thereof in
         accordance with the terms thereof), subject to no liens prior to the
         lien of the PSCO 1939 Mortgage other than "permitted encumbrances"; and
         the PSCO 1939 Mortgage by its terms effectively subjects to the lien
         thereof all property (except property of the kinds specifically
         excepted from the lien of the PSCO 1939 Mortgage) acquired by the
         Company after the date of the execution and delivery of the PSCO 1939
         Mortgage, subject to "permitted encumbrances", to any lien thereon
         existing at the time of such acquisition and to any liens for unpaid
         portions of the purchase money placed thereon at the time of such
         acquisition, and also subject to the provisions of Article XI of the
         PSCO 1939 Mortgage and to certain possible claims of a trustee in
         bankruptcy and possible claims and taxes of the federal government;

                                        5


                  (s)      The consolidated historical financial statements and
         schedules of the Company and its consolidated subsidiaries included or
         incorporated by reference in the Registration Statement and Prospectus
         present fairly in all material respects the financial condition,
         results of operations, cash flows and changes in financial position of
         the Company as of the dates and for the periods indicated, comply as to
         form with the applicable accounting requirements of the Act and the
         Exchange Act and have been prepared in conformity with GAAP throughout
         the periods involved (except as otherwise noted therein); the selected
         financial data set forth under the caption "Selected Consolidated
         Financial Data" in the Prospectus fairly present, on the basis stated
         in the Prospectus, the information included therein. Except as
         disclosed in or incorporated by reference in the Registration Statement
         and Prospectus, neither the Company nor any of its subsidiaries has any
         contingent obligations which are material to the Company and its
         consolidated subsidiaries taken as a whole;

                  (t)      Deloitte & Touche LLP, which audited the financial
         statements incorporated by reference in the Registration Statement and
         Prospectus, (A) are independent public accountants as required by the
         Act and the rules and regulations of the Commission thereunder and (B)
         do not provide to the Company or its subsidiaries any non-audit
         services which are prohibited by Section 10A(g) or (h) of the Exchange
         Act;

                  (u)      The statistical and market-related data and
         forward-looking statements (within the meaning of Section 27A of the
         Act and Section 21E of the Exchange Act) included or incorporated by
         reference in the Prospectus are based on or derived from sources that
         the Company believes to be reliable and accurate in all material
         respects and represent good faith estimates that are made on the basis
         of data derived from such sources;

                  (v)      Except as may otherwise be reflected in or
         contemplated by the Registration Statement and Prospectus, since the
         respective dates as of which information is given in the Registration
         Statement and Prospectus (i) there has been no material adverse change
         in the condition (financial or otherwise), prospects, earnings,
         business or properties of the Company and its subsidiaries taken as a
         whole, whether or not arising from transactions in the ordinary course
         of business and (ii) neither the Company nor any of its subsidiaries
         has entered into any transactions which are material to the Company and
         its subsidiaries taken as a whole, other than in the ordinary course of
         business; and, except as so reflected or contemplated, neither the
         Company nor any of its subsidiaries has any contingent obligations
         which are material to the Company and its subsidiaries taken as a
         whole;

                  (w)      Each of the Company and its subsidiaries has been
         duly incorporated and is validly existing as a corporation in good
         standing under the laws of the jurisdiction in which it is chartered or
         organized with full corporate power and authority to own or lease, as
         the case may be, and to operate its properties and conduct its business
         as described in the Registration Statement and Prospectus, and is duly
         qualified to do business as a foreign corporation and is in good
         standing under the laws of each jurisdiction in which such
         qualification is required, whether by reason of the ownership or
         leasing of property or the conduct of business, except where the
         failure to be so qualified would not have a material adverse change in
         the condition (financial or otherwise), prospects, earnings, business
         or properties of the Company and its subsidiaries taken as a whole,
         whether or not arising from transactions in the ordinary course of
         business;

                                        6


                  (x)      All the outstanding shares of capital stock of each
         subsidiary have been duly and validly authorized and issued and are
         fully paid and nonassessable, and, except as otherwise set forth in the
         Registration Statement and Prospectus, all outstanding shares of
         capital stock of the subsidiaries are owned by the Company either
         directly or through wholly-owned subsidiaries free and clear of any
         perfected security interest or any other security interests, claims,
         liens or encumbrances;

                  (y)      The Company has no subsidiaries which would be deemed
         significant subsidiaries under Regulation S-X;

                  (z)      Neither the Company nor any of its subsidiaries is in
         violation or default of (i) any provision of its charter or bylaws;
         (ii) the terms of any indenture, contract, lease, mortgage, deed of
         trust, note agreement, loan agreement or other agreement, obligation,
         condition, covenant or instrument to which it is a party or bound or to
         which its property is subject; or (iii) any statute, law, rule,
         regulation, judgment, order or decree applicable to the Company or any
         of its subsidiaries of any court, regulatory body, administrative
         agency, governmental body, arbitrator or other authority having
         jurisdiction over the Company or such subsidiary or any of its
         properties, as applicable except, in the case of clause (ii) or (iii),
         any such conflict, breach or violation which would not, individually or
         in the aggregate, have a material adverse change in the condition
         (financial or otherwise), prospects, earnings, business or properties
         of the Company and its subsidiaries taken as a whole, whether or not
         arising from transactions in the ordinary course of business;

                  (aa)     The Company, either directly or through its parent,
         has filed all foreign, federal, state and local tax returns that are
         required to be filed or has requested extensions thereof (except in any
         case in which the failure so to file would not have a material adverse
         effect on the condition (financial or otherwise), prospects, earnings,
         business or properties of the Company and its subsidiaries, taken as a
         whole, whether or not arising from transactions in the ordinary course
         of business, except as set forth in or contemplated in the Registration
         Statement and Prospectus and has paid, either directly or through its
         parent, all taxes required to be paid by it and any other assessment,
         fine or penalty levied against it, to the extent it has notice that any
         of the foregoing is due and payable, except for any such assessment,
         fine or penalty that is currently being contested in good faith or as
         would not have a material adverse effect on the condition (financial or
         otherwise), prospects, earnings, business or properties of the Company
         and its subsidiaries, taken as a whole, whether or not arising from
         transactions in the ordinary course of business, except as set forth in
         or contemplated in the Registration Statement and Prospectus;

                  (bb)     The Company and each of its subsidiaries are insured
         by insurers of recognized financial responsibility against such losses
         and risks and in such amounts as are prudent and customary in the
         businesses in which they are engaged; all material policies of
         insurance and fidelity or surety bonds insuring the Company or any of
         its subsidiaries or their respective businesses, assets, employees,
         officers and directors are in full force and effect; the Company and
         its subsidiaries are in compliance with the terms of such material
         policies and instruments in all material respects; and there are no
         material claims by the Company or any of its subsidiaries under any
         such policy or instrument as to which any insurance company is denying
         liability or defending under a reservation of rights clause; neither
         the Company nor any such subsidiary has been refused any material
         insurance coverage sought or applied for;

                                        7


                  (cc)     No subsidiary of the Company is currently prohibited,
         directly or indirectly, from paying any dividends to the Company, from
         making any other distribution on such subsidiary's capital stock, from
         repaying to the Company any loans or advances to such subsidiary from
         the Company or from transferring any of such subsidiary's property or
         assets to the Company or any other subsidiary of the Company, except as
         described in or contemplated by the Registration Statement and
         Prospectus;

                  (dd)     Neither the Company, nor any of its subsidiaries, nor
         any director, officer, agent, employee or other person or entity acting
         on behalf of the Company or any of its subsidiaries has, in the course
         of its actions for, or on behalf of, the Company, used any corporate
         funds for any unlawful contribution, gift, entertainment or other
         unlawful expenses relating to political activity; made any direct or
         indirect unlawful payment to any foreign or domestic government
         official or employee from corporate funds; violated or is in violation
         of any provision of the U.S. Foreign Corrupt Practices Act of 1977, as
         amended; or made any unlawful bribe, rebate, payoff, influence payment,
         kickback or other unlawful payment to any foreign or domestic
         government official or employee;

                  (ee)     (A) The Company has established and maintains
         disclosure controls and procedures (as such term is defined in Rule
         13a-15(e) under the Exchange Act, "Disclosure Controls"); and such
         Disclosure Controls are (i) designed to ensure that material
         information relating to the Company, including its consolidated
         subsidiaries, is properly recorded, processed, summarized and
         communicated to the Company's senior management, including its
         principal executive officer and its principal financial officer, by
         others within those entities as appropriate to allow timely decisions
         regarding required disclosure, (ii) evaluated by the Company's senior
         management on a quarterly basis and (iii) to the best knowledge of the
         Company, effective in all material respects to perform the functions
         for which they were established;

                           (B)      The Company has designed and maintains
         internal control over financial reporting (as such term is defined in
         Rule 13a-15(f) under the Exchange Act, "Reporting Controls"); and the
         Reporting Controls are (i) designed to provide reasonable assurance
         regarding the reliability of financial reporting and the preparation of
         financial statements for external purposes in accordance with GAAP and
         include, without limitation, those processes specifically referred to
         in Rule 13a-15(f) and (ii) to the best knowledge of the Company,
         effective to perform the functions for which they are maintained;

                           (C)      The Company has devised and maintains in
         effect a system of internal accounting controls ("Accounting
         Controls"); and such Accounting Controls are sufficient to provide
         reasonable assurances that (i) transactions involving the Company and
         its subsidiaries are executed in accordance with management's general
         or specific authorization; (ii) transactions are recorded as necessary
         (I) to permit preparation of financial statements in conformity with
         generally accepted accounting principles and (II) to maintain
         accountability for assets; (iii) access to assets is permitted only in
         accordance with management's general or specific authorization; and
         (iv) the recorded accountability for assets is compared with the
         existing assets at reasonable intervals and appropriate action is taken
         with respect to any differences;

                           (D)      Based on the most recent evaluation of the
         Company's internal controls referred to above, all significant
         deficiencies in the design or operation of such

                                        8


         internal controls which could adversely affect the Company's ability to
         record, process, summarize and report financial data required to be
         disclosed by the Company in its Exchange Act reports within the time
         periods specified in the Exchange Act, any material weaknesses in such
         internal controls and any fraud, whether or not material, that involves
         management or other employees who have a significant role in such
         internal controls have been identified and reported to the Company's
         auditors and the audit committee of the board of directors; and all
         such deficiencies and weaknesses, if any, have been rectified;

                  (ff)     Except as set forth in, or incorporated by reference
         in, the Registration Statement and Prospectus, the Company and its
         subsidiaries (i) are in compliance with any and all applicable federal,
         state and local laws and regulations relating to the protection of
         human health and safety, the environment or hazardous or toxic
         substances or wastes, pollutants or contaminants ("Environmental
         Laws"), (ii) have received all permits, licenses or other approvals
         required of them under applicable Environmental Laws to conduct their
         respective businesses, (iii) are in compliance with all terms and
         conditions of any such permits, licenses or approvals, and (iv) have
         not received notice of any actual or potential liability for the
         investigation or remediation of any disposal or release of hazardous or
         toxic substances or wastes, pollutants or contaminants, except where
         such non-compliance with Environmental Laws, failure to receive
         required permits, licenses or other approvals, or any such liability
         would not, individually or in the aggregate, have a material adverse
         change in the condition (financial or otherwise), prospects, earnings,
         business or properties of the Company and its subsidiaries, taken as a
         whole, whether or not arising from transactions in the ordinary course
         of business;

                  (gg)     With respect to each employee benefit plan (as
         defined in Section 3(3) of the Employee Retirement Income Security Act
         of 1974, as amended ("ERISA")) which the Company or any other
         organization that together with the Company is treated as a single
         employer under Sections 414(b), (c), (m) or (o) of the Internal Revenue
         Code of 1986, as amended (the "Code") (an "ERISA Affiliate"), has at
         any time sponsored, maintained, contributed to or been obligated to
         contribute to (a "Plan"): (i) the Company and each ERISA Affiliate have
         administered and operated each Plan sponsored or maintained by the
         Company or an ERISA Affiliate in compliance with ERISA, the Code and
         other applicable laws except for such instances of noncompliance as
         have not resulted in and could not reasonably be expected to result in
         a material liability to the Company or ERISA Affiliate; (ii) each Plan
         sponsored or maintained by the Company or an ERISA Affiliate intended
         to qualify under Section 401(a) of the Code so qualifies and to the
         Company's knowledge nothing has occurred, whether by action or failure
         to act, which could reasonably be expected to cause the loss of such
         qualification of any such Plan; (iii) neither the Company nor any ERISA
         Affiliate has incurred, and to the Company's knowledge no event,
         transaction or condition has occurred or exists under which the Company
         or any ERISA Affiliate could reasonably expect to incur, any material
         liability or the imposition of any lien on any of the rights,
         properties or assets of the Company or any ERISA Affiliate pursuant to
         Title I or Title IV of ERISA (other than routine claims for benefits)
         or applicable penalty or excise provisions of the Code; (iv) there has
         been no reportable event (within the meaning of Section 4043 of ERISA)
         with respect to any Plan subject to Title IV of ERISA that is sponsored
         or maintained by the Company or an ERISA Affiliate for which the 30-day
         reporting requirement has not been waived which could reasonably be
         expected to result in a material liability under Title IV of ERISA to
         the Company or an ERISA Affiliate; (v) no accumulated funding
         deficiency (within the meaning of Section 302 of ERISA and Section

                                        9


         412 of the Code), whether or not waived, exists with respect to any
         Plan subject to Title IV of ERISA that is sponsored or maintained by
         the Company; and (vi) neither the Company nor any ERISA Affiliate has
         incurred, and to the Company's knowledge no event, transaction or
         condition has occurred or exists under which the Company or any ERISA
         Affiliate could reasonably expect to incur, any material liability with
         respect to termination of, or withdrawal from, any Plan subject to
         Title IV of ERISA;

                  (hh)     The franchises held by the Company and its
         subsidiaries, together with the applicable Certificates of Convenience
         and Necessity issued by The Public Utilities Commission of the State of
         Colorado, give the Company and such subsidiaries all necessary
         authority for the maintenance and operation of their respective
         properties and business as now conducted, and are free from burdensome
         restrictions or conditions of an unusual character.

         Any certificate signed by any officer of the Company and delivered to
the Representatives or counsel for the Representatives in connection with the
offering of the Bonds shall be deemed a representation and warranty by the
Company, as to matters covered thereby, to each Underwriter.

         2.       Purchase and Sale. Subject to the terms and conditions and in
reliance upon the representations and warranties herein set forth, the Company
agrees to sell to each Underwriter, severally and not jointly, and each
Underwriter agrees, severally and not jointly, to purchase from the Company, (a)
at a purchase price of 99.280% of the principal amount thereof, plus accrued
interest, if any, from September 9, 2003 to the Closing Date, the principal
amount of 4.375% First Collateral Trust Bonds, Series No. 14 due 2008 set forth
opposite such Underwriter's name in Schedule I hereto and (b) at a purchase
price of 98.611% of the principal amount thereof, plus accrued interest, if any,
from September 9, 2003 to the Closing Date, the principal amount of 5.50% First
Collateral Trust Bonds, Series No. 15, due 2014 set forth opposite such
Underwriters name in Schedule 1 hereto.

         It is understood that the several underwriters propose to offer the
Bonds for sale to the public as set forth in the Prospectus.

         3.       Delivery and Payment. Delivery of and payment for the Bonds
shall be made at 10:00 A.M., New York City time, on September 9, 2003, or at
such time on such later date as the Representatives shall designate, which date
and time may be postponed by agreement between the Representatives and the
Company or as provided in Section 8 hereof (such date and time of delivery and
payment for the Bonds being herein called the "Closing Date"). Delivery of the
Bonds shall be made to the Representatives for the respective accounts of the
several Underwriters against payment by the several Underwriters through the
Representatives of the purchase price thereof to or upon the order of the
Company by wire transfer payable in same-day funds to the account specified by
the Company. Delivery of the Bonds shall be made through the facilities of The
Depository Trust Company.

         4.       Agreements. The Company agrees with each Underwriter:

                  (a)      To prepare the Prospectus in a form approved by the
         Representatives and to file such Prospectus pursuant to Rule 424(b)
         under the Act not later than the Commission's close of business on the
         second business day following the execution and delivery of this
         Agreement; to make no further amendment or any supplement to the
         Registration Statement or Prospectus prior to the Closing Date which
         shall be reasonably disapproved by the

                                       10


         Representatives promptly after reasonable notice thereof; during the
         period for which a prospectus is required to be delivered under the Act
         in connection with the offering and sale of the Bonds, to advise the
         Representatives, promptly after it receives notice thereof, of the time
         when any amendment to the Registration Statement has been filed or
         becomes effective or any supplement to the Prospectus or any amended
         Prospectus has been filed and to furnish the Representatives with
         copies thereof; to file promptly all reports and any definitive proxy
         or information statements required to be filed by the Company with the
         Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the
         Exchange Act subsequent to the date of the Prospectus and for so long
         as the delivery of a prospectus is required under the Act in connection
         with the offering or sale of the Bonds; to advise the Representatives,
         promptly after it receives notice thereof, of the issuance by the
         Commission of any stop order or of any order preventing or suspending
         the use of any prospectus, of the suspension of the qualification of
         the Bonds for offering or sale in any jurisdiction, of the initiation
         or threatening of any proceeding for any such purpose, or of any
         request by the Commission for the amending or supplementing of the
         Registration Statement or the Prospectus or for additional information;
         to use its best efforts to prevent the issuance of any stop order or of
         any order preventing or suspending the use of any prospectus or
         suspending any such qualification, and, in the event of the issuance of
         any such order, promptly to use its best efforts to obtain the
         withdrawal of such order;

                  (b)      Promptly from time to time to take such action as the
         Representatives may reasonably request to qualify the Bonds for
         offering and sale under the securities laws of such jurisdictions as
         the Representatives may request and to comply with such laws so as to
         permit the continuance of sales and dealings therein in such
         jurisdictions for as long as may be necessary to complete the
         distribution of the Bonds, provided that in connection therewith the
         Company shall not be required to qualify as a foreign corporation or to
         file a general consent to service of process in any jurisdiction;

                  (c)      Prior to 10:00 a.m., New York City time, on the third
         Business Day next succeeding the date of this Agreement and from time
         to time, to furnish the Underwriters with written and electronic copies
         of the Prospectus in such quantities as the Representatives may from
         time to time reasonably request, and, if the delivery of a prospectus
         is required under the Act at any time in connection with the offering
         or sale of the Bonds and if at such time any event shall have occurred
         as a result of which the Prospectus as then amended or supplemented
         would include an untrue statement of a material fact or omit to state
         any material fact necessary in order to make the statements therein, in
         the light of the circumstances under which they were made when such
         Prospectus is delivered, not misleading, or, if for any other reason it
         shall be necessary during such period to amend or supplement the
         Prospectus or to file under the Exchange Act any document incorporated
         by reference in the Prospectus in order to comply with the Act, the
         Exchange Act or the Trust Indenture Act, to notify the Representatives
         and upon their reasonable request to file such document and to prepare
         and furnish without charge to each Underwriter and to any dealer in
         securities as many written and electronic copies as the Representatives
         may from time to time reasonably request of an amended Prospectus or a
         supplement to the Prospectus which will correct such statement or
         omission or effect such compliance;

                  (d)      To make generally available to its securityholders
         and to the Representatives as soon as practicable, but in any event not
         later than eighteen months after the effective date of the Registration
         Statement (as defined in Rule 158(c) under the Act), an earnings

                                       11


         statement of the Company and its subsidiaries (which need not be
         audited) covering a period of at least 12 months beginning after the
         later of (i) the effective date of the most recent post-effective
         amendment to the Registration Statement to become effective prior to
         the date of this Agreement and (ii) the date of the Company's most
         recent Annual Report on Form 10-K filed with the Commission prior to
         the date of this Agreement, which will satisfy the provisions of
         Section 11(a) of the Act and the rules and regulations thereunder
         including Rule 158;

                  (e)      For a period of 14 days following the Execution Time,
         without the prior written consent of the Representatives, not to offer,
         sell or contract to sell, or otherwise dispose of (or enter into any
         transaction which is designed to, or might reasonably be expected to,
         result in the disposition (whether by actual disposition or effective
         economic disposition due to cash settlement or otherwise) by the
         Company, directly or indirectly, or announce the offering of) any
         long-term debt securities issued or guaranteed by the Company, other
         than the Bonds and the bonds contemplated by any Shelf Registration
         Statement or Exchange Offer Registration Statement (as such terms are
         defined in the Registration Rights Agreement dated March 14, 2003,
         between the Company and Banc One Capital Markets Inc. and UBS
         Securities LLC, as representatives of the Initial Purchasers (as
         identified therein));

                  (f)      To use the net proceeds received by it from the sale
         of the Bonds pursuant to this Agreement in the manner specified in the
         Prospectus under the caption "Use of Proceeds";

                  (g)      To pay the costs and expenses relating to the
         following matters: (i) the preparation of the Supplemental Indenture
         the issuance of the Bonds and the fees of the Trustee; (ii) the
         preparation, printing and filing of the Registration Statement
         (including all exhibits thereto), the preliminary prospectus, the
         Prospectus (including all documents incorporated by reference therein)
         and any amendments thereof or supplements thereto and the printing and
         furnishing of such copies of each thereof to the Underwriters and to
         dealers (including postage, air freight charges and charges for
         counting and packaging), as may be reasonably requested for use in
         connection with the offering and sale of the Bonds; (iii) the
         preparation, printing, authentication, issuance and delivery of
         certificates for the Bonds, including any stamp or transfer taxes in
         connection with the original issuance and sale of the Bonds; (iv) the
         printing (or reproduction) and delivery of this Agreement, any blue sky
         memorandum and all other agreements or documents printed (or
         reproduced) and delivered in connection with the offering of the Bonds;
         (v) any registration or qualification of the Bonds for offer and sale
         under the securities or blue sky laws of the several states (including
         filing fees and the reasonable fees and expenses of counsel for the
         Underwriters relating to such registration and qualification); (vi) the
         transportation and other expenses incurred by or on behalf of Company
         representatives in connection with presentations to prospective
         purchasers of the Bonds; (vii) the fees and expenses of the Company's
         accountants and counsel (including local and special counsel); (viii)
         the fees and expenses of any rating agencies rating the Bonds and (ix)
         all other costs and expenses incident to the performance by the Company
         of its obligations hereunder.

         5.       Conditions to the Obligations of the Underwriters. The
obligations of the Underwriters to purchase the Bonds shall be subject to the
accuracy of the representations and warranties on the part of the Company
contained herein at the Execution Time and the Closing Date,

                                       12


to the accuracy of the statements of the Company made in any certificates
pursuant to the provisions hereof, to the performance by the Company of its
obligations hereunder and to the following additional conditions:

                  (a)      (i) The Prospectus shall have been filed with the
         Commission pursuant to Rule 424(b) within the applicable time period
         prescribed for such filing by the rules and regulations under the Act
         and in accordance with Section 4(a) hereof; (ii) no stop order
         suspending the effectiveness of the Registration Statement or any part
         thereof shall have been issued and no proceeding for that purpose shall
         have been initiated or threatened by the Commission; and (iii) all
         requests for additional information on the part of the Commission shall
         have been complied with to the Representatives' reasonable
         satisfaction;

                  (b)      At the Closing Date, the Representatives shall have
         received opinions, dated the Closing Date, of Ann E. Hopfenbeck,
         Assistant General Counsel, Xcel Energy Services, Attorney for the
         Company, Jones Day and LeBoeuf, Lamb, Greene and MacRae, LLP, counsel
         for the Company, substantially to the effect set forth in Exhibit A
         hereto and other related matters as the Representatives may reasonably
         require, with reproduced or conformed copies thereof for each of the
         Purchasers, and the Company shall have furnished to such counsel such
         documents as they request for the purpose of enabling them to pass upon
         such matters;

                  (c)      At the Closing Date, the Representatives shall have
         received from Dewey Ballantine LLP, counsel for the Underwriters, such
         opinion or opinions, dated the Closing Date and addressed to the
         Representatives, with respect to the issuance and sale of the Bonds,
         the Indenture, the Registration Statement, the Prospectus and other
         related matters as the Representatives may reasonably require, and the
         Company shall have furnished to such counsel such documents as they
         request for the purpose of enabling them to pass upon such matters;

                  (d)      The Company shall have furnished to the
         Representatives a certificate of the Company, signed by the President
         or any Vice President and the Treasurer of the Company, dated the
         Closing Date, to the effect that the signer of such certificate has
         carefully examined the Registration Statement and all amendments
         thereto, the Prospectus and all amendments or supplements thereto and
         this Agreement and that:

                           (i)      the representations and warranties of the
         Company in this Agreement are true and correct in all material respects
         on and as of the Closing Date with the same effect as if made on the
         Closing Date, and the Company has complied with all the agreements and
         satisfied all the conditions on its part to be performed or satisfied
         hereunder at or prior to the Closing Date; and

                           (ii)     since the date of the most recent financial
         statements included or incorporated by reference in the Prospectus,
         there has been no material adverse change in the condition (financial
         or otherwise), prospects, earnings, business or properties of the
         Company and its subsidiaries taken as a whole, whether or not arising
         from transactions in the ordinary course of business, except as set
         forth in or contemplated by the Prospectus.

                  (e)      At the Execution Time and at the Closing Date, the
         Company shall have requested and caused Deloitte & Touche LLP to
         furnish to the Representatives letters, dated

                                       13


         respectively as of the Execution Time and as of the Closing Date,
         substantially to the effect set forth in Exhibit B hereto;

                  (f)      Subsequent to the Execution Time or, if earlier, the
         dates as of which information is given in the Prospectus, there shall
         not have been (i) any change or decrease specified in the letter or
         letters referred to in paragraph (e) of this Section 5; or (ii) any
         change, or any development involving a prospective change, in or
         affecting the financial condition, business or properties of the
         Company and its subsidiaries, taken as a whole, whether or not arising
         from transactions in the ordinary course of business, except as set
         forth in or contemplated in the Prospectus the effect of which, in any
         case referred to in clause (i) or (ii) above, is, in the sole judgment
         of the Representatives, so material and adverse as to make it
         impractical or inadvisable to market the Bonds as contemplated by the
         Prospectus.

                  (g)      Subsequent to the Execution Time, there shall not
         have been any decrease in the rating or outlook of any of the Company's
         debt securities by any "nationally recognized statistical rating
         organization" (as defined for purposes of Rule 436(g) under the Act) or
         any public announcement of any intended or potential decrease in any
         such rating or outlook or of a possible change in any such rating or
         outlook that does not indicate the direction of the possible change;

                  (h)      The Company shall have complied with the provisions
         of Section 4(c) hereof with respect to the furnishing of prospectuses.

                  (i)      Prior to the Closing Date, the Company shall have
         furnished to the Representatives such further information, certificates
         and documents as the Representatives may reasonably request.

         If any of the conditions specified in this Section 5 shall not have
been fulfilled in all material respects when and as provided in this Agreement,
or if any of the opinions and certificates mentioned above or elsewhere in this
Agreement shall not be in all material respects reasonably satisfactory in form
and substance to the Representatives and counsel for the Underwriters, this
Agreement and all obligations of the Underwriters hereunder may be cancelled at,
or at any time prior to, the Closing Date by the Representatives. Notice of such
cancellation shall be given to the Company in writing or by telephone or
facsimile confirmed in writing.

         The documents required to be delivered by this Section 5 will be
delivered at the office of counsel for the Company, at Jones Day, on the Closing
Date.

         6.       Reimbursement of Expenses. If the sale of the Bonds provided
for herein is not consummated because any condition to the obligations of the
Underwriters set forth in Section 5 hereof is not satisfied, because of any
termination pursuant to clause (i) of Section 9 hereof or because of any
refusal, inability or failure on the part of the Company to perform any
agreement herein or comply with any provision hereof, other than by reason of a
default by any of the Underwriters, the Company will reimburse the Underwriters
on demand for all out-of-pocket expenses (including reasonable fees and
disbursements of counsel) that shall have been incurred by them in connection
with the proposed purchase and sale of the Bonds.

         7.       Indemnification and Contribution. (a) The Company agrees to
indemnify and hold harmless each Underwriter, the directors, members, officers,
employees and agents of each

                                       14


Underwriter and each person who controls any Underwriter within the meaning of
either the Act or the Exchange Act against any and all losses, claims, damages
or liabilities, joint or several, to which they or any of them may become
subject under the Act, the Exchange Act or other Federal or state statutory law
or regulation, at common law or otherwise, insofar as such losses, claims,
damages or liabilities (or actions in respect thereof) arise out of or are based
upon any untrue statement or alleged untrue statement of a material fact
contained in the Registration Statement or any amendment thereto, in any
preliminary prospectus or preliminary prospectus supplement or in the Prospectus
or any amendment or supplement thereto, or arise out of or are based upon the
omission or alleged omission to state therein 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, and agrees to
reimburse each such indemnified party, as incurred, for any legal or other
expenses reasonably incurred by them in connection with investigating or
defending any such loss, claim, damage, liability or action; provided, however,
that the Company will not be liable in any such case to the extent that any such
loss, claim, damage or liability arises out of or is based upon any such untrue
statement or alleged untrue statement or omission or alleged omission made in
the Registration Statement or any amendment thereto, in any preliminary
prospectus or preliminary prospectus supplement or in the Prospectus or any
amendment or supplement thereto, in reliance upon and in conformity with written
information furnished to the Company by or on behalf of any Underwriter through
the Representatives specifically for inclusion therein; provided, further, that
with respect to any such untrue statement in or omission from any preliminary
prospectus, the indemnity contained in this paragraph (a) shall not inure to the
benefit of any Underwriter or its directors, members, officers, employees and
agents, and each person, if any, who controls such Underwriter to the extent
that the sale to the person asserting any such loss, claim, damage or liability
was an initial sale by such Underwriter and any such loss, claim, damage or
liability of or with respect to such Underwriter results from the fact that both
(i) to the extent required by applicable law, a copy of the Prospectus was not
sent or given to such person at or prior to the written confirmation of the sale
of the Bonds to such person and (ii) the untrue statement in or omission from
such preliminary prospectus was corrected in the Prospectus unless, in either
case, such failure to deliver the Prospectus was a result of non-compliance by
the Company with the provisions of Section 4(c) hereof. This indemnity agreement
will be in addition to any liability which the Company may otherwise have;

                  (b)      Each Underwriter severally and not jointly agrees to
indemnify and hold harmless the Company, and each of its directors, officers,
employees and agents, and each person who controls the Company within the
meaning of either the Act or the Exchange Act, to the same extent as the
foregoing indemnity from the Company to each Underwriter, but only with
reference to written information relating to such Underwriter furnished to the
Company by or on behalf of such Underwriter through the Representatives
specifically for inclusion in the Prospectus or any amendment or supplement
thereto. This indemnity agreement will be in addition to any liability which
such Underwriter may otherwise have. The Company acknowledges that the
statements set forth in (i) the last sentence of the cover page of the
Prospectus regarding the delivery of the Bonds, (ii) the third paragraph of text
under the caption "Underwriting" in the Prospectus, (iii) the first, second and
third sentences of the sixth paragraph of text under the caption "Underwriting"
in the Prospectus and (iv) the seventh and eighth paragraphs of text under the
caption "Underwriting" in the Prospectus constitute the only information
furnished in writing by or on behalf of the Underwriters for inclusion in the
Prospectus (or any amendment or supplement thereto);

                  (c)      Promptly after receipt by an indemnified party under
this Section 7 of notice of the commencement of any action, such indemnified
party will, if a claim in respect thereof is to be made against the indemnifying
party under this Section 7, notify the indemnifying party in writing of

                                       15


the commencement thereof; but the failure so to notify the indemnifying party
(i) will not relieve it from liability under paragraph (a) or (b) above unless
and to the extent it did not otherwise learn of such action and such failure
results in the forfeiture by the indemnifying party of substantial rights and
defenses; and (ii) will not, in any event, relieve the indemnifying party from
any obligations to any indemnified party other than the indemnification
obligation provided in paragraph (a) or (b) above. The indemnifying party shall
be entitled to appoint counsel of the indemnifying party's choice at the
indemnifying party's expense to represent the indemnified party in any action
for which indemnification is sought (in which case the indemnifying party shall
not thereafter be responsible for the fees and expenses of any separate counsel
retained by the indemnified party or parties except as set forth below);
provided, however, that such counsel shall be reasonably satisfactory to the
indemnified party. Notwithstanding the indemnifying party's election to appoint
counsel to represent the indemnified party in an action, the indemnified party
shall have the right to employ separate counsel (including local counsel), and
the indemnifying party shall bear the reasonable fees, costs and expenses of
such separate counsel if (i) the use of counsel chosen by the indemnifying party
to represent the indemnified party would present such counsel with a conflict of
interest; (ii) the actual or potential defendants in, or targets of, any such
action include both the indemnified party and the indemnifying party and the
indemnified party shall have reasonably concluded that there may be legal
defenses available to it and/or other indemnified parties which are different
from or additional to those available to the indemnifying party; (iii) the
indemnifying party shall not have employed counsel satisfactory to the
indemnified party to represent the indemnified party within a reasonable time
after notice of the institution of such action; or (iv) the indemnifying party
shall authorize the indemnified party to employ separate counsel at the expense
of the indemnifying party, it being understood, however, that in each case the
indemnifying party 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 (in
addition to any local counsel) at any time for all such indemnified parties,
which firm shall be designated by the Representatives if the indemnified parties
consist of the Underwriters or their directors, members, officers, employees or
agents. An indemnifying party will not, without the prior written consent of the
indemnified parties, settle or compromise or consent to the entry of any
judgment with respect to any pending or threatened claim, action, suit or
proceeding in respect of which indemnification or contribution may be sought
hereunder (whether or not the indemnified parties are actual or potential
parties to such claim or action) unless such settlement, compromise or consent
includes an unconditional release of each indemnified party from all liability
arising out of such claim, action, suit or proceeding;

                  (d)      In the event that the indemnity provided in paragraph
(a) or (b) of this Section 7 is for any reason held to be unenforceable by an
indemnified party although applicable in accordance with its terms, the Company
and the Underwriters agree to contribute to the aggregate losses, claims,
damages and liabilities (including legal or other expenses reasonably incurred
in connection with investigating or defending same) (collectively, "Losses") to
which the Company and one or more of the Underwriters may be subject in such
proportion as is appropriate to reflect the relative benefits received by the
Company on the one hand and by the Underwriters on the other from the offering
of the Bonds; provided, however, that in no case shall any Underwriter (except
as may be provided in any agreement among the Underwriters relating to the
offering of the Bonds) be responsible for any amount in excess of the purchase
discount or commission applicable to the Bonds purchased by such Underwriter
hereunder; provided, further, that each Underwriter's obligation to contribute
to Losses hereunder shall be several and not joint. If the allocation provided
by the immediately preceding sentence is unavailable for any reason, the Company
and the Underwriters shall contribute in such proportion as is appropriate to
reflect not only such relative benefits but also

                                       16


the relative fault of the Company on the one hand and of the Underwriters on the
other in connection with the statements or omissions which resulted in such
Losses, as well as any other relevant equitable considerations. Benefits
received by the Company shall be deemed to be equal to the total net proceeds
from the offering (before deducting expenses) received by it, and benefits
received by the Underwriters shall be deemed to be equal to the total
underwriting discounts and commissions in each case set forth on the cover of
the Prospectus Supplement. Relative fault shall be determined by reference to,
among other things, whether any untrue or any alleged untrue statement of a
material fact or the omission or alleged omission to state a material fact
relates to information provided by the Company on the one hand or the
Underwriters on the other, the intent of the parties and their relative
knowledge, information and opportunity to correct or prevent such untrue
statement or omission. The Company and the Underwriters agree that it would not
be just and equitable if contribution were determined by pro rata allocation or
any other method of allocation which does not take account of the equitable
considerations referred to above. Notwithstanding the provisions of this
paragraph (d), 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. For purposes of
this Section 7, each person who controls an Underwriter within the meaning of
either the Act or the Exchange Act and each director, member, officer, employee
and agent of an Underwriter shall have the same rights to contribution as such
Underwriter, and each person who controls the Company within the meaning of
either the Act or the Exchange Act and each officer, director, member, employee
or agent of the Company shall have the same rights to contribution as the
Company, subject in each case to the applicable terms and conditions of this
paragraph (d);

         8.       Default by an Underwriter. If any one or more Underwriters
shall fail to purchase and pay for any of the Bonds agreed to be purchased by
such Underwriter hereunder and such failure to purchase shall constitute a
default in the performance of its or their obligations under this Agreement, the
remaining Underwriters shall be obligated severally to take up and pay for (in
the respective proportions which the amount of Bonds set forth opposite their
names in Schedule I hereto bears to the aggregate amount of Bonds set forth
opposite the names of all the remaining Underwriters) the Bonds which the
defaulting Underwriter or Underwriters agreed but failed to purchase; provided,
however, that in the event that the aggregate amount of Bonds which the
defaulting Underwriter or Underwriters agreed but failed to purchase shall
exceed 10% of the aggregate amount of Bonds set forth in Schedule I hereto, the
remaining Underwriters shall have the right to purchase all, but shall not be
under any obligation to purchase any, of the Bonds, and if such nondefaulting
Underwriters do not purchase all the Bonds, this Agreement will terminate
without liability to any nondefaulting Underwriter or the Company. In the event
of a default by any Underwriter as set forth in this Section 8, the Closing Date
shall be postponed for such period, not exceeding five Business Days, as the
Representatives shall determine in order to effect whatever changes may thereby
be made necessary in the Registration Statement or the Prospectus or any
amendment or supplement to either thereof, or in any other documents or
arrangements, and the Company agrees to file promptly any amendments or
supplements to the Registration Statement or the Prospectus which in the opinion
of the Representatives may thereby be made necessary. The term "Underwriter" as
used in this Agreement shall include any person substituted under this Section
with like effect as if such person had originally been a party to this
Agreement. Nothing contained in this Agreement shall relieve any defaulting
Underwriter of its liability, if any, to the Company or any nondefaulting
Underwriter for damages occasioned by its default hereunder.

         9.       Termination. This Agreement shall be subject to termination in
the absolute discretion of the Representatives, by notice given to the Company
prior to delivery of and payment

                                       17


for the Bonds, if at any time after the date hereof and prior to the delivery of
and payment for the Bonds (i) trading in the common stock of Xcel Energy Inc.
shall have been suspended by the Commission or the New York Stock Exchange or
trading in securities generally on the New York Stock Exchange shall have been
suspended or limited or minimum prices shall have been established on such
Exchange; (ii) a banking moratorium shall have been declared either by Federal
or New York State authorities; (iii) there shall have occurred a material
disruption in commercial banking or securities settlement or clearance services
in the United States or Europe; or (iv) there shall have occurred any outbreak
or escalation of hostilities, declaration by the United States of a national
emergency or war or other calamity or crisis the effect of which on financial
markets is such as to make it, in the sole judgment of the Representatives,
impracticable or inadvisable to proceed with the offering or delivery of the
Bonds as contemplated by the Prospectus.

         10.      Indemnities to Survive. The respective agreements,
representations, warranties, indemnities and other statements of the Company or
its officers and of the Underwriters set forth in or made pursuant to this
Agreement will remain in full force and effect, regardless of any investigation
made by or on behalf of the Underwriters or the Company or any of the officers,
directors or controlling persons referred to in Section 7 hereof, and will
survive delivery of and payment for the Bonds. The provisions of Sections 6 and
7 hereof shall survive the termination or cancellation of this Agreement.

         11.      Notices. All communications hereunder will be in writing and
effective only on receipt, and, if sent to the Representatives, will be mailed,
delivered or telefaxed to Banc One Capital Markets, Inc., at fax no. (312)
732-4773, and confirmed to Banc One Capital Markets, Inc., 1 Bank One Plaza,
Suite IL1 0595, 8th Floor, Chicago, Illinois 60670, Attention: Structuring &
Execution, and to McDonald Investments Inc., 800 Superior Avenue, Cleveland,
Ohio 44114, and to UBS Securities LLC, at fax no. (203) 719-0495, and confirmed
to UBS Securities LLC, 677 Washington Blvd., Stamford, Connecticut 06901,
Attention: Fixed Income Syndicate; or, if sent to the Company, will be mailed,
delivered or telefaxed to Public Service Company of Colorado, 1225 17th Street,
Denver, Colorado 80202, Attention: Vice President and Treasurer (fax no.: (612)
215-5445) and confirmed to the General Counsel (fax no.: (612) 215-4501).

         12.      Successors. This Agreement will inure to the benefit of and be
binding upon the parties hereto and their respective successors and the officers
and directors and controlling persons referred to in Section 7 hereof, and no
other person will have any right or obligation hereunder.

         13.      Applicable Law. This Agreement will be governed by and
construed in accordance with the laws of the State of New York applicable to
contracts made and to be performed within the State of New York.

         14.      Counterparts. This Agreement may be executed in one or more
counterparts, each of which shall constitute an original and all of which
together shall constitute one and the same instrument.

         15.      Headings. The section headings used herein are for convenience
only and shall not affect the construction hereof.

         16.      Definitions. The terms which follow, when used in this
Agreement, shall have the meanings indicated.

                                       18


         "Act" shall mean the Securities Act of 1933, as amended, and the rules
and regulations of the Commission promulgated thereunder.

         "Business Day" shall mean any day other than a Saturday, a Sunday or a
legal holiday or a day on which banking institutions or trust companies are
authorized or obligated by law to close in the City of New York.

         "Closing Date" shall have the meaning specified in Section 3 hereof.

         "Commission" shall mean the Securities and Exchange Commission.

         "Exchange Act" shall mean the Securities Exchange Act of 1934, as
amended, and the rules and regulations of the Commission promulgated thereunder.

         "Execution Time" shall mean the date and time that this Agreement is
executed and delivered by the parties hereto.

         "GAAP" shall mean United States generally accepted accounting
principles applied on a consistent basis.

         "Mortgage Supplement" shall mean the Supplemental Indenture, dated as
of September 1, 2003, between the Company and U.S. Bank Trust National
Association, as trustee, supplemental to the PSCO 1939 Mortgage.

         "Trust Indenture Act" shall mean the Trust Indenture Act of 1939, as
amended, and the rules and regulations of the Commission promulgated thereunder.

         17.      Underwriters' Counsel. The Company and the Underwriters
acknowledge that Dewey Ballantine LLP (a) is acting as counsel to the
Underwriters in connection with this Agreement and the transactions contemplated
hereby and (b) has acted, and may continue to act, as counsel to the Company's
parent company, Xcel Energy Inc., and certain of its subsidiaries in connection
with certain regulatory matters, and the Company and the Underwriters consent to
such representation.

                                       19


         If the foregoing is in accordance with your understanding of our
agreement, please sign and return to us the enclosed duplicate hereof, whereupon
this Agreement and your acceptance shall represent a binding agreement between
the Company and the several Underwriters.

                                        Very truly yours,

                                        PUBLIC SERVICE COMPANY OF
                                          COLORADO

                                        By: /s/ Benjamin G. S. Fowke III
                                            -----------------------------
                                        Name: Benjamin G. S. Fowke III
                                        Title: Vice President and Treasurer

The foregoing Agreement is hereby confirmed
and accepted as of the date first above written.

BANC ONE CAPITAL MARKETS, INC.
MCDONALD INVESTMENTS INC.
UBS SECURITIES LLC

For themselves and the other several
Underwriters named in Schedule I to the
foregoing Agreement.

By: UBS SECURITIES LLC

By: /s/ Christopher Forshner
    ----------------------------
Name: Christopher Forshner
Title: Executive Director

By: /s/ Scott Whitney
    ----------------------------
Name: Scott Whitney
Title: Director



                                   SCHEDULE I



                                                                                  Principal Amount     Principal Amount
                                                                                  of 4.375% First       of 5.50% First
                                                                                  Collateral Trust     Collateral Trust
                                                                                   Bonds due 2008       Bonds due 2014
                               Underwriters                                       to be Purchased      to be Purchased
                               ------------                                       ----------------     ----------------
                                                                                                 
Banc One Capital Markets, Inc..................................................   $     80,000,000     $     73,333,334
McDonald Investments Inc.                                                         $     80,000,000     $     73,333,333
UBS Securities LLC ............................................................   $     80,000,000     $     73,333,333
U.S. Bancorp Piper Jaffray Inc.................................................   $     24,000,000     $     22,000,000
Wells Fargo Brokerage Services, LLC............................................   $     24,000,000     $     22,000,000
Citigroup Global Markets, Inc. ................................................   $     12,000,000     $     11,000,000
                                                                                  ----------------     ----------------

                  Total........................................................   $    300,000,000     $    275,000,000



                                                                     EXHIBIT A-1

                      FORM OF OPINION OF ANN E. HOPFENBECK

Ladies and Gentlemen:

                  For the purpose of rendering this opinion, I have examined the
proceedings taken by Public Service Company of Colorado, a Colorado corporation
(the "Company"), with respect to the issue and sale by the Company of $
300,000,000 principal amount of 4.375% First Collateral Trust Bonds, Series No.
14 due 2008 and $ 275,000,000 principal amount of 5.50% First Collateral Trust
Bonds, Series No. 15 due 2014 (collectively, the "Bonds"). In connection
therewith I have participated in the preparation of the proceedings for the
issuance and sale of the Bonds including the Underwriting Agreement dated
September 2, 2003, between you and the Company relating to your purchase of the
Bonds (the "Agreement"), and have either participated in the preparation of or
examined the Trust Indenture dated October 1, 1993, from the Company to U.S.
Bank Trust National Association, as successor trustee (the "Trustee"), as
heretofore supplemented and as it will be further supplemented by Supplemental
Indenture No. 15 creating the Bonds (said indenture, as so supplemented and to
be further supplemented, being hereafter referred to as the "Indenture") and the
PSCo 1939 Mortgage (as defined in the Indenture). This letter is furnished to
the Underwriters pursuant to Section 5(b) of the Agreement. Except as otherwise
defined herein, terms used in this letter that are defined in the Agreement are
used herein as so defined. I also have participated in the preparation of or
examined the registration statement and any amendments thereto and the
accompanying prospectuses and any amendments or supplements thereto, as filed
under the Act, with respect to the Bonds. My examination has extended to all
statutes, records, instruments, and documents which I have deemed necessary to
examine for the purposes of this opinion.

                  I am of the opinion that:

                  1.       The Company has been duly incorporated and is validly
         existing as a corporation in good standing under the laws of the State
         of Colorado with corporate power and authority to own, lease and
         operate its properties and conduct its business as described in the
         Prospectus and to enter into and perform its obligations under the
         Agreement;

                  2.       The Agreement has been duly authorized, executed and
         delivered by the Company;

                  3.       The issuance and sale of the Bonds, and the issuance
         and delivery of the Class A Bonds, have been duly authorized and
         approved by an order of The Public Utilities Commission of the State of
         Colorado and such order is final and in full force and effect on the
         date hereof, the time for appeal therefrom or review thereof or
         intervention with respect thereto having expired; no further approval,
         authorization, consent or other order of any public board or body in
         the State of Colorado is legally required in connection with the
         transactions contemplated by the Agreement, the Indenture or the PSCo
         1939 Mortgage, except as may be required under the blue sky laws of any
         jurisdiction in connection with the purchase and distribution of the
         Bonds by the Underwriters in the manner contemplated by the Agreement
         and in the Prospectus;

                                      A-1-1


                  4.       Neither the execution and delivery of the Agreement,
         the issue and sale of the Bonds, nor the consummation of any other of
         the transactions therein contemplated, nor the fulfillment of the terms
         thereof will conflict with, result in a breach or violation or
         imposition of any lien, charge or encumbrance upon any property or
         assets of the Company or any of its subsidiaries, other than the
         security interest created by the Bonds, the Indenture and the PSCo 1939
         Mortgage, under (i) the Restated Articles of Incorporation, as amended,
         or By-Laws of the Company or any of its subsidiaries; (ii) the terms of
         any indenture, contract, lease, mortgage, deed of trust, note
         agreement, loan agreement or other agreement, obligation, condition,
         covenant or instrument to which the Company or any of its subsidiaries
         is a party or bound or to which its or their property is subject; or
         (iii) any statute, law, rule, regulation, judgment, order or decree
         applicable to the Company or any of its subsidiaries of any court,
         regulatory body, administrative agency, governmental body, arbitrator
         or other authority having jurisdiction over the Company or any of its
         subsidiaries or any of its or their properties except, in the case of
         clause (ii) or (iii), any such conflict, breach or violation, if it did
         exist, would not, individually or in the aggregate, have a material
         adverse change in the condition (financial or otherwise), prospects,
         earnings, business or properties of the Company and its subsidiaries
         taken as a whole, whether or not arising from transactions in the
         ordinary course of business;

                  5.       The facsimile signature of a Senior Vice President or
         Vice President of the Company in lieu of his manual signature on the
         Bonds and the Class A Bonds and the facsimile signature of the
         Secretary or an Assistant Secretary of the Company attesting the
         corporate seal in lieu of his manual signature on the Bonds and the
         Class A Bonds have been duly and properly authorized by the Board of
         Directors of the Company, are not inconsistent with the provisions of
         the Restated Articles of Incorporation, as amended, or By-Laws of the
         Company and are valid and effective under the laws of the State of
         Colorado; and the facsimile signatures of such officers on the Bonds
         and the Class A Bonds have the same legal effect as though they had
         manually signed and attested the Bonds and the Class A Bonds as such
         respective officers;

                  6.       The descriptions in the Registration Statement and
         Prospectus of Colorado state statutes and legal and governmental
         proceedings are accurate in all material respects; to the best of my
         knowledge, there are no franchises, contracts, indentures, mortgages,
         loan agreements, notes, leases or other instruments that would be
         required to be described in the documents incorporated by reference in
         the Prospects that are not described or referred to in such
         incorporated documents, and the descriptions thereof or references
         thereto are correct in all material respects;

                  7.       There is no pending, or to my knowledge, threatened
         suit or proceeding before any court or governmental agency, authority
         or body or any arbitration involving the Company or any of its
         subsidiaries required to be disclosed in the Prospectus which is not
         adequately disclosed in the Prospectus; and

                  8.       The franchises held by the Company, together with the
         applicable Certificates of Convenience and Necessity issued by The
         Public Utilities Commission of the State of Colorado, give the Company
         all necessary authority for the maintenance and operation of its
         properties and business as now conducted, and are free from burdensome
         restrictions or conditions of an unusual character.

                  In the course of my participation in the preparation or
examination of the Registration Statement and any amendments thereto and the
Prospectus and any amendments or supplements thereto

                                      A-1-2


I made investigations as to the accuracy of certain of the statements of fact
contained therein, I discussed other matters with officers, employees, and
representatives of the Company, and I examined various corporate records and
data. While I do not pass upon or assume responsibility for, and shall not be
deemed to have independently verified, the accuracy and completeness of the
statements contained in the Registration Statement or the Prospectus (except as
to matters set forth in paragraphs 6 and 7 above), nothing has come to my
attention that would lead me to believe that the Registration Statement, at the
time it became effective, contained an untrue statement of a material fact or
omitted to state a material fact required to be stated therein or necessary in
order to make the statements therein, not misleading, or that the Prospectus, at
the time it was filed with the Commission pursuant to Rule 424(b) under the Act
and at the date hereof, contained or contains an untrue statement of material
fact or omitted or omits 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.

                  My opinions herein are limited to the laws of the State of
Colorado. For purposes of rendering their opinion of even date herewith to the
Underwriters, Dewey Ballantine LLP are entitled to rely on my opinions in
paragraphs 1, 2 and 3 above as to all matters of Colorado law as if such
opinions were addressed to them.

                                        Respectfully submitted,

                                        By: ____________________________________
                                            Ann E. Hopfenbeck
                                            Assistant General Counsel
                                            Xcel Energy Services, Inc.

                                      A-1-3


                                                                     EXHIBIT A-2

                          FORM OF OPINION OF JONES DAY

Ladies and Gentlemen:

                  We have acted as special counsel to Public Service Company of
Colorado, a Colorado corporation (the "Company"), in connection with the sale by
the Company pursuant to the Underwriting Agreement, dated as of September 2,
2003 (the "Agreement"), by and among the Company and the Underwriters named on
Schedule I thereto (the "Underwriters"), for whom you are acting as
representatives (the "Representatives"), of $300,000,000 aggregate principal
amount of 4.375% First Collateral Trust Bonds, Series 14 due 2008, and
$275,000,000 aggregate principal amount of 5.50% First Collateral Trust Bonds,
Series 15 due 2014 of the Company (collectively, the "Bonds") being issued on
this date under the Company's Indenture, dated as of October 1, 1993, to U.S.
Bank Trust National Association, as successor trustee (the "Trustee"), as
heretofore supplemented and as it is being further supplemented by a
supplemental indenture creating the Bonds (said Indenture, as so supplemented,
being hereafter referred to as the "Indenture"). This letter is furnished to the
Underwriters pursuant to Section 5(b) of the Agreement. Except as otherwise
defined herein, terms used in this letter that are defined in the Agreement are
used herein as so defined.

                  In connection with the opinions expressed herein, we have
examined such documents and records, including an examination of originals or
copies certified or otherwise identified to our satisfaction, and matters of law
as we have deemed necessary for purposes of this opinion. Based upon the
foregoing and subject to the further assumptions, qualifications and limitations
stated herein, we are of the opinion that:

                  1.       Assuming that the Agreement has been duly (a)
         authorized by the Company and (b) executed and delivered by the Company
         under Colorado law, the Agreement has been duly executed and delivered
         by the Company to the extent such execution and delivery are questions
         of New York law.

                  2.       The Company is not, and after giving effect to the
         offering and sale of the Bonds and the application of the proceeds
         thereof as described in the Prospectus will not be, an "investment
         company" or an entity "controlled" by an "investment company" within
         the meaning of the Investment Company Act of 1940, as amended, without
         taking account of any exemption arising out of the number of holders of
         the Company's securities.

                  3.       Assuming that the issuance and sale of the Bonds, and
         the issuance and delivery of the Class A Bonds, have been duly
         authorized and approved by an order of The Public Utilities Commission
         of the State of Colorado and such order is final and in full force and
         effect on the date hereof, and that the time for appeal therefrom or
         review thereof or intervention with respect thereto have expired, no
         approval, authorization, consent or order of any public board or body
         under the laws of the United States of America is legally required in
         connection with the transactions contemplated by the Agreement, the
         Indenture or the PSCo 1939 Mortgage, except those that already have
         been obtained and are in full force and effect.

                                      A-2-1


                  4.       The Registration Statement has been declared
         effective by the Commission under the Act, the Prospectus has been
         filed with the Commission pursuant to Rule 424(b) under the Act in the
         manner and within the time period required by Rule 424(b) under the
         Act; and no stop order suspending the effectiveness of the Registration
         Statement has been issued under the Act and, to the best of our
         knowledge, no proceedings for that purpose have been instituted or are
         pending or are threatened by the Commission;

                  5.       Except as to the financial statements or other
         financial or statistical data included or incorporated by reference
         therein, as to which we express no opinion, the Registration Statement,
         at the time it became effective, and the Prospectus, at the time it was
         filed with the Commission pursuant to Rule 424(b), complied as to form
         in all material respects with the applicable requirements of the Act
         and the Trust Indenture Act.

                  6.       Except as to the financial statements or other
         financial or statistical data included or incorporated by reference
         therein, as to which we express no opinion, the documents incorporated
         by reference in the Prospectus, when they were filed with the
         Commission, compiled as to form in all material respects with the
         applicable requirements of the Exchange Act.

                  7.       The descriptions in the Registration Statement and
         the Prospectus of United States federal statutes are accurate and
         fairly present the information purported to be given.

                  We have not independently verified and are not passing upon,
and do not assume any responsibility for, the accuracy, completeness or
fairness, except and to the extent as set forth in paragraph 8 above, of the
information included in the Registration Statement or Prospectus. We have
participated in the preparation of the Registration Statement and Prospectus.
From time to time in connection therewith, we have had discussions with
officers, directors and employees of the Company and Xcel Energy Inc., a
Minnesota corporation and the parent corporation of the Company, with
representatives of Deloitte & Touche LLP, the independent accountants who
examined certain of the financial statements of the Company, and with the
Underwriters and counsel to the Underwriters. Based upon our participation and
discussions described above, nothing has come to our attention that would lead
us to believe that the Registration Statement, at the time it became effective,
contained an untrue statement of a material fact or omitted to state a material
fact required to be stated therein or necessary in order to make the statements
therein, not misleading, or that the Prospectus, at the time it was filed with
the Commission pursuant to Rule 424(b) under the Act and at the date hereof,
contained or contains an untrue statement of material fact or omitted or omits
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 (except
that we express no view as to the financial statements, financial schedules and
other financial data included or incorporated by reference in the Prospectus).

                  The opinions and views set forth above are subject to the
following assumptions, qualifications and limitations:

                  We have assumed, for purposes of the opinions and views
expressed herein, the legal capacity of all natural persons executing documents,
the genuineness of all signatures, the authenticity of original and certified
documents and the conformity to original or certified copies of all copies
submitted to us as conformed or reproduction copies. For the purposes of the
opinions and views expressed herein, we also have assumed that each of the
Underwriters and the Trustee has duly authorized, executed and delivered the
documents to which each of them is a party and that each of

                                      A-2-2


such documents is the valid, binding and enforceable obligation of each of the
Underwriters and the Trustee, respectively.

                  Our examination of matters of law in connection with the
opinions expressed herein have been limited to, and accordingly our opinions
herein are limited to, the federal laws of the United States of America and the
laws of the State of New York, in each case as currently in effect. In
connection with our opinions set forth herein, we express no opinion as to any
matters of, or that relate to, the laws of any other jurisdiction, including the
laws of the State of Colorado. To the extent such opinions relate to any
provision of Colorado law, we direct you to the opinion dated the date hereof of
Ann E. Hopfenbeck, Esq., Assistant General Counsel of Xcel Energy Services, Inc.
and a member of the Colorado bar, which opinion previously has been delivered to
you.

                  It should be understood that the scope of our representation
does not include providing legal services to any financial institution or
financial institution-affiliated party with regard to any matter (a "financial
institutions regulatory matter") the resolution of which requires reference to
any provision of Title 12 of the United States Code as in effect from time to
time, the policies, procedures, guidelines or practices of any state regulator
with respect to any such federal or state law or regulation, or any other
federal or state law or regulation or regulatory policy, procedure or practice
expressly applicable to financial institutions or, in their capacities as such,
financial institution-affiliated parties or, if not expressly applicable, then
to the extent applicable by implication or actually applied to a financial
institution or financial institution-affiliated party. We express no opinion
regarding the compliance by any Underwriter with any such financial institutions
regulatory matter.

                  This letter is furnished by us, as special counsel to the
Company, to you, as the Representatives, solely for the benefit of the
Underwriters and solely with respect to the purchase of the Bonds from the
Company by the Underwriters upon the understanding that we are not hereby
assuming any professional responsibility to any other person whatsoever, and
that this letter is not to be used, circulated, quoted or otherwise referred to
for any other purpose.

                                        Very truly yours,

                                      A-2-3


                                                                     EXHIBIT A-3

            FORM OF OPINION OF LEBOEUF, LAMB, GREENE & MACRAE, L.L.P.

Ladies and Gentlemen:

                  We have acted as counsel to Public Service Company of Colorado
(the "Company"), with respect to matters relating to the Indenture dated as of
December 31, 1939 (the "1939 PSCo Mortgage") between the Company and U.S. Bank
Trust National Association (formerly First Trust of New York, National
Association), as successor trustee (the "1939 Trustee"), and the Indenture dated
as of October 1, 1993, as amended and supplemented (the "Indenture"), between
the Company and U.S. Bank Trust National Association (formerly First Trust of
New York, National Association), as successor trustee (the "Trustee") in
connection with the sale by the Company of $300,000,000 aggregate principal
amount of its First Collateral Trust Bonds, Series No. 14 due 2008 and
$275,000,000 aggregate principal amount of its First Collateral Trust Bonds,
Series No. 15 due 2014 (collectively, the "Bonds") on the basis of an equivalent
amount of Class A Bonds (as defined in the Indenture). This opinion is being
delivered pursuant to Section 5(b) of the Underwriting Agreement, dated
September 2, 2003 (the "Agreement"), between the Company and you as
representatives of the Underwriters (the "Representatives"). Unless otherwise
stated, defined terms used herein shall have the respective meanings given to
them in the Agreement.

                  We are not general counsel to the Company and our
representation of the Company consists of advising it with respect to corporate
and regulatory matters as to which we have been specifically consulted. We are
familiar with the legal matters pertaining to, and the corporate proceedings of
the Company taken with respect to, the authorization and the issuance and sale
by the Company of the Bonds and the authorization and the issuance and delivery
by the Company of the Class A Bonds. We have examined, among other things, the
Registration Statement and Prospectus and any amendment and supplement thereto,
the corporate records of the Company, the Indenture (including the Supplemental
Indenture creating the Bonds), the PSCo 1939 Mortgage (including the
supplemental indenture thereto under which the Class A Bonds are being issued),
and such other proceedings, papers and documents as we have deemed relevant for
the purposes of rendering the opinions enumerated below. In such examination, we
have assumed the genuineness of all signatures, the authenticity of all
documents submitted to us as originals, the conformity to the original documents
of all documents submitted to us as copies and the authenticity of all such
latter documents. We have relied as to various questions of fact upon
discussions with officers and representatives of the Company and the
representations and warranties of the Company contained in the Agreement and
upon the certificates of public officials and of officers of the Company being
delivered to you thereunder. With respect to the opinions expressed in
paragraphs 5, 6 and 7 below, we have relied upon information obtained from
public records and from the Company.

                  On the basis of and subject to the foregoing, and subject to
the further limitations and qualifications set forth below, it is our opinion
that:

                  1.       The Indenture has been duly and validly authorized,
         executed and delivered by the Company and is in due and proper form and
         (assuming the Indenture has been duly authorized, executed and
         delivered by the Trustee) constitutes a legal, valid and binding

                                      A-2-1


         mortgage of the Company, enforceable in accordance with its terms,
         subject to bankruptcy, insolvency, moratorium, fraudulent conveyance
         and transfer, and other similar laws affecting the rights of mortgagees
         and creditors generally, state laws which affect the enforcement of
         certain remedial provisions of the Indenture, and general principles of
         equity (regardless of whether such principles are considered in a
         proceeding at law or in equity); provided, however, that such state
         laws which affect the enforcement of certain remedial provisions of the
         Indenture will not, in our opinion, render the remedies afforded by the
         Indenture inadequate for the practical realization of the benefit of
         the security provided thereby;

                  2.       The Bonds are in due and proper form and the issuance
         and sale of the Bonds have been duly authorized by all necessary
         corporate action, and when duly executed, authenticated and delivered
         to the Underwriters pursuant to the Agreement against payment of the
         consideration set forth therein, the Bonds will be legal, valid and
         binding obligations of the Company enforceable (subject to the
         exceptions and limitations referred to in paragraph 1 hereof) in
         accordance with their terms and entitled to the benefits and security
         of the Indenture; and the Bonds will be secured equally and ratably
         with all other bonds outstanding under the Indenture;

                  3.       The PSCo 1939 Mortgage has been duly and validly
         authorized, executed and delivered by the Company and is in due and
         proper form and (assuming the PSCo 1939 Mortgage has been duly
         authorized, executed and delivered by the 1939 Trustee) constitutes a
         legal, valid and binding mortgage of the Company, enforceable in
         accordance with its terms, subject to bankruptcy, insolvency,
         moratorium, fraudulent conveyance and transfer, and other similar laws
         affecting the rights of mortgagees and creditors generally, state laws
         which affect the enforcement of certain remedial provisions of the PSCo
         1939 Mortgage and general principles of equity (regardless of whether
         such principles are considered in a proceeding at law or in equity);
         provided, however, that such state laws which affect the enforcement of
         certain remedial provisions of the Indenture will not, in our opinion,
         render the remedies afforded by the PSCo 1939 Mortgage inadequate for
         the practical realization of the benefit of the security provided
         thereby;

                  4.       The Class A Bonds are in due and proper form and the
         issuance and delivery of the Class A Bonds have been duly authorized by
         all necessary corporate action; and when (a) the Class A Bonds have
         been duly executed, authenticated and delivered to the Trustee pursuant
         to the PSCo 1939 Mortgage and (b) the Bonds have been duly executed,
         authenticated and delivered to the Underwriters pursuant to the
         Agreement against payment of the consideration set forth therein, the
         Class A Bonds will be legal, valid and binding obligations of the
         Company enforceable (subject to the exceptions and limitations referred
         to in paragraph 3 hereof) in accordance with their terms and entitled
         to the benefits and security of the PSCo 1939 Mortgage; and the Class A
         Bonds will be secured equally and ratably with all other bonds
         outstanding under the PSCo 1939 Mortgage (except to the extent that any
         sinking, amortization, improvement or other fund may afford additional
         security for such bonds of any particular series);

                  5.       The Company has good title to the real properties
         specifically or generally described or referred to in the Indenture and
         in the PSCo 1939 Mortgage as subject to the respective liens thereof
         (except such real property as may have been sold, exchanged or
         otherwise disposed of), subject only to (a) in the case of all such
         properties, the lien of the PSCo 1939 Mortgage and "permitted
         encumbrances" (as defined in the PSCo 1939 Mortgage) and (b)

                                      A-2-2


         in the case of such properties which are used or to be used in or in
         connection with the Electric Utility Business (as defined in the
         Indenture) (whether or not such use is the sole use of such property),
         the lien of the Indenture and Permitted Liens (as defined in the
         Indenture);

                  6.       The Indenture and the filings and recordations made
         in connection therewith constitute a mortgage lien on the properties
         specifically or generally described or referred to therein as subject
         to the lien thereof (except such properties as may have been sold,
         exchanged or otherwise disposed of or released from the lien thereof in
         accordance with the terms thereof), subject to no liens prior to the
         lien of the Indenture other than Permitted Liens and the lien of the
         PSCo 1939 Mortgage; and the Indenture by its terms effectively subjects
         to the lien thereof all property (except property of the kinds
         specifically excepted from the lien of the Indenture by the terms
         thereof) acquired by the Company after the date of execution and
         delivery of the Indenture and used or to be used in or in connection
         with the Electric Utility Business, subject to Permitted Liens, the
         lien of the PSCo 1939 Mortgage, any lien thereon existing at the time
         of such acquisition and to any liens for unpaid portions of the
         purchase money placed thereon at the time of such acquisition, and also
         subject to the provisions of Article Thirteen of the Indenture and to
         certain possible claims of a trustee in bankruptcy and possible claims
         and taxes of the federal government;

                  7.       The PSCo 1939 Mortgage and the filings and
         recordations made in connection therewith constitute a first mortgage
         lien on the properties specifically or generally described or referred
         to therein as subject to the lien thereof (except such property as may
         have been sold, exchanged or otherwise disposed of or released from the
         lien thereof in accordance with the terms thereof), and, with respect
         to the shares of stock pledged thereunder, the PSCo 1939 Mortgage and
         the possession by the Trustee of such stock and appropriate stock
         powers in the State of New York pursuant to the PSCo 1939 Mortgage is
         sufficient to create a security interest under Article 9 of the Uniform
         Commercial Code as in effect in the State of New York with respect to
         such stock (except such stock as may have been sold, exchanged or
         otherwise disposed of or released from the lien thereof in accordance
         with the terms thereof), subject to no liens or security interests
         prior to the lien and security interest created by the PSCo 1939
         Mortgage other than "permitted encumbrances"; and the PSCo 1939
         Mortgage by its terms effectively subjects to the lien or security
         interest thereof all property (except property of the kinds
         specifically excepted from the lien of the PSCo 1939 Mortgage by the
         terms thereof) acquired by the Company after the date of execution and
         delivery of the PSCo 1939 Mortgage, subject to "permitted
         encumbrances", to any lien thereon existing at the time of such
         acquisition and to any liens for unpaid portions of the purchase money
         placed thereon at the time of acquisition and also subject to the
         provisions of Article XI of the PSCo 1939 Mortgage and to certain
         possible claims of a trustee in bankruptcy and possible claims and
         taxes of the federal government; and

                  8.       The Bonds, the Indenture, the Class A Bonds, and the
         PSCo 1939 Mortgage conform as to legal matters to the descriptions of
         the terms thereof contained in the Prospectus under the captions
         "Supplemental Description of the First Collateral Trust Bonds,"
         "Description of the First Collateral Trust Bonds" and "Description of
         the 1939 Mortgage".

                  This opinion is limited to the laws of the State of New York
and the State of Colorado and the federal law of the United States of America.
This opinion speaks as of the date hereof and we undertake no responsibility to
advise you of any change in circumstances after the date hereof.

                                      A-2-3


                  Dewey Ballantine LLP is hereby authorized to rely upon
paragraphs 1, 2, 3, 4 and 8 of this letter as to matters governed by the law of
the State of Colorado as if this letter, solely with respect to aforementioned
paragraphs, were addressed to them.

                  This letter is not being delivered for the benefit of, nor may
it be relied upon by, the holders of the Bonds or any other party to which it is
not specifically addressed or to which reliance has not expressly been permitted
hereby. This letter may be relied upon only by the addressees hereof in
connection with the issuance and sale of the Bonds and may not be relied upon
for any other purpose.

                                        Very truly yours,

                                      A-2-4


                                                                       EXHIBIT B

                     FORM OF LETTER OF DELOITTE & TOUCHE LLP

                                      A-3-1