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                                                                     Exhibit 1.2



                            HL&P Capital Trust ___


                     _____% Capital Securities, Series ___
            guaranteed to the extent set forth in the Guarantee by

                       Houston Lighting & Power Company

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

                            Underwriting Agreement
                            ----------------------
                                                               ________ __, 19__
Goldman, Sachs & Co.
Merrill Lynch, Pierce, Fenner
 & Smith Incorporated
c/o Goldman, Sachs & Co.
85 Broad Street,
New York, New York 10004

Ladies and Gentlemen:

          HL&P Capital Trust ___, a statutory business trust created under the
laws of the State of Delaware (the "Trust"), and Houston Lighting & Power
Company, a Texas corporation, as depositor of the Trust and as guarantor (the
"Guarantor"), propose, subject to the terms and conditions stated herein, that
the Trust issue and sell to the Underwriters named in Schedule I hereto (the
"Underwriters") an aggregate of [$___________] liquidation amount of ______%
Capital Securities, Series ___ (liquidation amount $1,000 per capital security)
(the "Securities") representing undivided beneficial interests in the assets of
the Trust, guaranteed by the Guarantor as to the payment of distributions, and
as to payments on liquidation or redemption, to the extent set forth in a
guarantee agreement (the "Guarantee") among the Guarantor and The Bank of New 
York, as trustee (the "Guarantee Trustee"). The proceeds of the sale of the
Securities and an aggregate of [$__________] liquidation amount of its Common
Securities (liquidation amount $1,000 per common security) (the "Common
Securities") by the Trust are to be invested in Junior Subordinated Debentures,
Series ___ (the "Subordinated Debentures") of the Guarantor to be issued
pursuant to an Indenture (the "Indenture") among the Guarantor and The Bank of 
New York, as trustee (the "Debenture Trustee").

          1.  Representations and Warranties of the Guarantor and the Trust.
              -------------------------------------------------------------  
(a)  The Guarantor and the Trust jointly and severally represent and warrant to,
and agree with, each of the Underwriters that:
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          (i) A registration statement on Form S-3 with respect to the
              Securities, the Subordinated Debentures and the Guarantee (File
              Nos. 333-____ and 333-____) including a prospectus (any
              preliminary prospectus included in such registration statement
              being hereinafter referred to as a "Preliminary Prospectus"),
              copies of which have been delivered to you, has been prepared and
              filed by the Guarantor and the Trust with the Securities and
              Exchange Commission (the "Commission") and has been declared
              effective under the Securities Act of 1933, as amended (the
              "Act"). No stop order suspending the effectiveness of such
              registration statement has been issued and no proceeding for that
              purpose has been initiated or, to the best knowledge of the
              Guarantor and the Trust, threatened by the Commission. Such
              registration statement (including all documents filed as part
              thereof or incorporated by reference therein, but excluding any
              Forms T-1, as amended), as amended and supplemented at the date of
              this Agreement is hereinafter referred to as to the "Registration
              Statement." The Prospectus contained in the Registration Statement
              at the time that the Registration Statement was declared effective
              is hereinafter referred to as the "Basic Prospectus."

                 The prospectus included in the Registration Statement, as
              amended and supplemented to the date of this Agreement (including
              all documents then incorporated by reference therein and including
              the Preliminary Supplemented Prospectus (hereinafter defined) as
              further supplemented by the Final Supplemented Prospectus
              (hereinafter defined)), is hereinafter referred to as the
              "Prospectus". Any reference herein to the Registration Statement,
              the Prospectus, a Preliminary Prospectus, the Basic Prospectus,
              the Preliminary Supplemented Prospectus or the Final Supplemented
              Prospectus shall be deemed to refer to and include the documents
              incorporated by reference therein, or deemed to be incorporated by
              reference therein, and filed under the Securities Exchange Act of
              1934, as amended (the "Exchange Act"), on or before the date of
              such Registration Statement, Prospectus, Preliminary Prospectus,
              the Basic Prospectus, the Preliminary Supplemented Prospectus or
              the Final Supplemented Prospectus. Any reference herein to the
              terms "amend", "amendment" or "supplement" with respect to the
              Registration Statement or the Prospectus shall be deemed to refer
              to and include, without limitation, the filing of any document
              under the Exchange Act deemed to be incorporated therein by
              reference after the date of such Registration Statement or
              Prospectus.

                 A prospectus supplement, dated, subject to completion, January
              __, 1997, as supplemented and amended, is hereinafter called the
              "Preliminary Supplemented Prospectus". A prospectus supplement,
              dated the date hereof, setting forth the terms of the Securities
              and of their sale and distribution (the "Final Supplemented
              Prospectus") has been prepared and will be filed pursuant to Rule
              424(b) under the Act ("Rule 424(b)").

                                       2
<PAGE>
 
          (ii)   On the effective date of the Registration Statement, the
                 Registration Statement, as amended and supplemented at that
                 time, conformed in all material respects to the requirements of
                 the Act and the Trust Indenture Act of 1939, as amended (the
                 "TIA"), and the applicable rules and regulations of the
                 Commission thereunder, and did not include any untrue statement
                 of a material fact or omit to state any material fact required
                 to be stated therein or necessary to make the statements
                 therein not misleading; on the date of the Preliminary
                 Supplemented Prospectus, the Preliminary Supplemented
                 Prospectus conformed in all material respects to the
                 requirements of the Act and the TIA and the applicable rules
                 and regulations of the Commission thereunder, and did not
                 include any untrue statement of a material fact or omit to
                 state any material fact required to be stated therein or
                 necessary to make the statements therein not misleading; and on
                 the date of this Agreement, the Registration Statement and the
                 Prospectus conform, and at the Time of Delivery (hereinafter
                 defined) they will conform, in all material respects to the
                 requirements of the Act and the TIA and the applicable rules
                 and regulations of the Commission thereunder, and on the date
                 of this Agreement do not, and on the Time of Delivery will not,
                 contain any untrue statement of a material fact or omit to
                 state any material fact required to be stated therein or
                 necessary to make the statements therein not misleading;

          (iii)  Each document filed or to be filed pursuant to the Exchange Act
                 and incorporated by reference, or deemed to be incorporated by
                 reference in the Prospectus (including any document to be filed
                 pursuant to the Exchange Act which will constitute an amendment
                 to the Prospectus) conformed or, when so filed, will conform in
                 all material respects to the requirements of the Exchange Act
                 and the applicable rules and regulations of the Commission
                 thereunder, and none of such documents included or, when so
                 filed, will include any untrue statement of a material fact or
                 omitted or, when so filed, will omit to state any 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;

          (iv)   The Trust has been duly created and is validly existing as a
                 business trust in good standing under the laws of the State of
                 Delaware, with power and authority to own, lease and operate
                 its properties and conduct its business as described in the
                 Prospectus and, based on expected operations and law in effect
                 on the date hereof, the Trust will be classified as a grantor
                 trust and will not be classified as an association taxable as a
                 corporation for United States federal income tax purposes;

          (v)    This Agreement has been duly authorized, executed and delivered
                 by the Guarantor and the Trust;

          (vi)   The Securities have been duly authorized by the Trust
                 Agreement, and, when issued and delivered pursuant to this
                 Agreement, such

                                       3
<PAGE>
 
                 Securities will be duly and validly issued and, subject to the
                 qualifications set forth herein, fully paid and non-assessable
                 undivided beneficial interests in the assets of the Trust
                 entitled to the benefits provided by the Amended and Restated
                 Trust Agreement (the "Trust Agreement") among the Guarantor and
                 the Trustees named therein (the "Trustees")(subject to the
                 terms of the Trust Agreement); provided that the holders of
                 Securities (the "Securityholders") may be obligated, pursuant
                 to the Trust Agreement, to (a) provide indemnity and/or
                 security in connection with and pay taxes or governmental
                 charges arising from transfers or exchanges of Securities
                 certificates and the issuance of replacement Securities
                 certificates and (b) provide security and indemnity in
                 connection with requests of or directions to the Property
                 Trustee (as defined in the Trust Agreement) to exercise its
                 rights and remedies under the Trust Agreement; and the
                 Securities conform to the description thereof contained in the
                 Final Supplemented Prospectus;

          (vii)  The Securityholders will be entitled to the same limitation of
                 personal liability extended to stockholders of private
                 corporations for profit organized under the General Corporation
                 Law of the State of Delaware;

          (viii)  The Common Securities of the Trust have been duly authorized
                  by the Trust Agreement, and upon delivery by the Trust to the
                  Guarantor against payment therefor as set forth in the Trust
                  Agreement, will be duly and validly issued undivided
                  beneficial interests in the assets of the Trust and conform to
                  the description thereof contained in the Final Supplemented
                  Prospectus; the issuance of the Common Securities of the Trust
                  is not subject to preemptive or other similar rights; and at
                  the Time of Delivery, all of the issued and outstanding Common
                  Securities of the Trust will be directly owned by the
                  Guarantor free and clear of any security interest, mortgage,
                  pledge, lien, encumbrance, claim or equity;

          (ix)   The Guarantee, the Trust Agreement, the Subordinated
                 Debentures, the Indenture and the Agreement as to Expenses and
                 Liabilities between the Guarantor and the Trust (the "Expense
                 Agreement") (the Guarantee, the Trust Agreement, the
                 Subordinated Debentures, the Indenture and the Expense
                 Agreement being collectively referred to as the "Guarantor
                 Agreements") have each been duly authorized by the Guarantor
                 and when validly executed and delivered by the Guarantor and,
                 in the case of the Guarantee, by the Guarantee Trustee, in the
                 case of the Trust Agreement, by the Trustees and, in the case
                 of the Indenture, by the Debenture Trustee, and, in the case of
                 the Subordinated Debentures, when validly issued by the
                 Guarantor and duly authenticated and delivered by the Debenture
                 Trustee, will constitute valid and legally binding obligations
                 of the Guarantor, enforceable in accordance with their
                 respective terms, subject, as to enforcement, to bankruptcy,
                 insolvency, reorganization and other laws of general
                 applicability relating to or

                                       4
<PAGE>
 
                 affecting creditors' rights and to general equity principles
                 (regardless of whether such enforceability is considered in a
                 proceeding in equity or at law); the Subordinated Debentures
                 when validly issued by the Guarantor and duly authenticated and
                 delivered by the Debenture Trustee, will be entitled to the
                 benefits of the Indenture; and the Guarantor Agreements conform
                 to the descriptions thereof in the Final Supplemented
                 Prospectus;

          (x)    The issue and sale of the Securities by the Trust, the
                 compliance by the Trust with all of the provisions of this
                 Agreement, the Securities and the Trust Agreement, the purchase
                 of the Subordinated Debentures by the Trust, the execution,
                 delivery and performance by the Trust of the Trust Agreement
                 and the consummation of the transactions contemplated herein
                 and therein will not conflict with or result in a breach or
                 violation of any of the terms or provisions of, or constitute a
                 default under, any indenture, mortgage, deed of trust, loan
                 agreement or other agreement or instrument to which the Trust
                 is a party or by which the Trust is bound or to which any of
                 the property or assets of the Trust is subject, nor will such
                 action result in any violation of the provisions of the Trust
                 Agreement or any existing statute or any order, rule or
                 regulation of any court or governmental agency or body having
                 jurisdiction over the Trust or any of its properties; the
                 Commission has issued an order under the Act declaring the
                 Registration Statement effective and qualifying the Guarantee,
                 the Trust Agreement and the Indenture under the TIA and no
                 other consent, approval, authorization, order, registration or
                 qualification of or with any such court or governmental agency
                 or body is required for the issue and sale of the Securities
                 and the Common Securities by the Trust, the purchase of the
                 Subordinated Debentures by the Trust or the consummation by the
                 Trust of the transactions contemplated by this Agreement,
                 except such consents, approvals, authorizations, registrations
                 or qualifications as may be required under state securities or
                 Blue Sky laws in connection with the purchase and distribution
                 of the Securities by the Underwriters;

          (xi)   The issuance by the Guarantor of the Guarantee and the
                 Subordinated Debentures, the compliance by the Guarantor with
                 all of the provisions of this Agreement, the Guarantee, the
                 Subordinated Debentures, the Trust Agreement, the Indenture and
                 the Expense Agreement, the execution, delivery and performance
                 by the Guarantor of the Guarantor Agreements, and the
                 consummation of the transactions contemplated herein and
                 therein will not conflict with or result in a breach or
                 violation of any of the terms or provisions of, or constitute a
                 default under, any indenture, mortgage, deed of trust, loan
                 agreement or other agreement or instrument for borrowed money
                 to which the Guarantor or any Significant Subsidiary (as
                 defined by Regulation S-X) is a party or by which the
                 Guarantor or any Significant Subsidiary is bound or to which
                 any of the property or assets of the Guarantor or any
                 Significant Subsidiary is subject, nor will such action result
                 in any violation of the provisions of the Restated Articles of
                 Incorporation or Amended and Restated By-laws of the Guarantor
                 or any existing statute or any order, rule or regulation of any
                 court or governmental agency or body having jurisdiction over
                 the Guarantor or any of its or its Significant Subsidiaries'
                 properties; the Commission has issued an order under the Act
                 declaring the Registration Statement effective and qualifying 
                 the Guarantee, the Trust Agreement and the Indenture under 
                 the TIA
                                       5
<PAGE>
 
                 and no other consent, approval, authorization, order,
                 registration or qualification of or with any such court or
                 governmental agency or body is required for the issue of the
                 Guarantee or the Subordinated Debentures or the consummation by
                 the Guarantor of the other transactions contemplated by this
                 Agreement or the Guarantor Agreements, except such consents,
                 approvals, authorizations, registrations or qualifications as
                 may be required under state securities or Blue Sky laws in
                 connection with the issuance by the Guarantor of the Guarantee
                 and the Subordinated Debentures;

          (xii)  The Trust is not and, after giving effect to the offering and
                 sale of the Securities, will not be an "investment company", or
                 an entity "controlled" by an "investment company", as such
                 terms are defined in the Investment Company Act of 1940, as
                 amended (the "Investment Company Act");

             2.     Sale and Delivery.  (a)  Subject to the terms and conditions
                    -----------------                                           
herein set forth, the Guarantor and the Trust agree to issue and sell to each of
the Underwriters, and each of the Underwriters agrees, severally and not
jointly, to purchase from the Trust, at a purchase price of 100% of the
liquidation amount thereof, the liquidation amount of Securities set forth
opposite the name of such Underwriters in Schedule I hereto.

             (b)    As compensation to the Underwriters for their commitments
hereunder, and in view of the fact that the proceeds of the sale of the
Securities will be issued by the Trust to purchase the Subordinated Debentures
of the Guarantor, the Guarantor hereby agrees to pay at the Time of Delivery to
Goldman, Sachs & Co., for the accounts of the several Underwriters, an amount
equal to $[ ] per Security for the Securities to be delivered at the Time of
Delivery by wire transfer of Federal (same-day) funds. The total aggregate
amount of the Underwriters' compensation is $_______________.

             (c)    Except as set forth in the next paragraph, the Securities to
be purchased by each Underwriter hereunder will be represented by one or more
definitive global Securities in book-entry form which will be deposited by or on
behalf of the Trust with The Depository Trust Company ("DTC") or its designated
custodian. The Trust will deliver the Securities to Goldman, Sachs & Co., for
the account of each Underwriter, against payment by or on behalf of such
Underwriter of the purchase price therefor by wire transfer of Federal (same
day) funds to a commercial bank account located in the United States and
designated in writing at least forty-eight hours prior to the Time of Delivery
by the Guarantor to Goldman, Sachs & Co., by causing DTC to credit the
Securities to the account of Goldman, Sachs & Co. at DTC. The Trust will cause
the global certificates representing the Securities to be made available to
Goldman, Sachs & Co. for checking at least twenty-four hours prior to the Time
of Delivery at the office of DTC or its designated custodian (the "Designated
Office"). The time and date of such delivery and payment shall be 9:30 a.m., New
York City time, on ________ __, 19__ or such other time and date as Goldman,
Sachs & Co. and the Guarantor may agree upon in writing. Such time and date are
herein called the "Time of Delivery".

                                       6
<PAGE>
 
          (d)  The documents to be delivered at the Time of Delivery by or on
behalf of the parties hereto pursuant to Section 5 hereof, including the cross-
receipt for the Securities and any additional documents requested by the
Underwriters pursuant to Section 5(k) hereof, will be delivered at such time and
date at the offices of Dewey Ballantine, 1301 Avenue of the Americas, New York,
New York 10019 or such other location as Goldman Sachs & Co. and the Guarantor
may agree in writing (the "Closing Location"), and the Securities will be
delivered at the Designated Office, all at the Time of Delivery. A meeting will
be held at the Closing Location at 1:00 p.m., New York City time, or such other
time as Goldman Sachs & Co. and the Guarantor may agree in writing on the New
York Business Day next preceding the Time of Delivery, at which meeting the
final drafts of the documents to be delivered pursuant to the preceding sentence
will be available for review by the parties hereto. For the purposes of this
Section 2, "New York Business Day" shall mean each Monday, Tuesday, Wednesday,
Thursday and Friday which is not a day on which banking institutions in New York
are generally authorized or obligated by law or executive order to close.

          3.   Covenants and Agreements.  The Guarantor and the Trust jointly
               ------------------------                                      
and severally covenant and agree with each of the Underwriters:

          (a)  That the Guarantor will furnish without charge to the
Underwriters a copy of the Registration Statement, including all documents
incorporated by reference therein and exhibits filed with the Registration
Statement (other than exhibits which are incorporated by reference and have
previously been so furnished), and, during the period mentioned in paragraph (c)
below, as many copies of the Prospectus, the Preliminary Supplemented Prospectus
and the Final Supplemented Prospectus, any documents incorporated by reference
therein at or after the date thereof (including documents from which information
has been so incorporated) and any supplements and amendments thereto as each
Underwriter may reasonably request so long as such Underwriter is required to
deliver a prospectus;

          (b)  That the Guarantor will cause the Final Supplemented Prospectus
to be filed pursuant to, and in compliance with, Rule 424(b) and will promptly
advise the Underwriters (i) when any amendment to the Registration Statement
shall have been filed; provided, that, with respect to documents filed pursuant
                       -------- 
to the Exchange Act and incorporated by reference into the Registration
Statement, such notice shall only be required during such time as the
Underwriters are required in the reasonable opinion of Dewey Ballantine, counsel
for the Underwriters, to deliver a prospectus, (ii) of any request by the
Commission for any amendment of the Registration Statement, (iii) of the
issuance by the Commission of any stop order suspending the effectiveness of the
Registration Statement or the institution or threatening of any proceeding for
that

                                       7
<PAGE>
 
purpose, and (iv) of the receipt by the Guarantor or the Trust of any
notification with respect to the suspension of the qualification of the
Securities for sale in any jurisdiction or the initiation or threatening of any
proceeding for such purpose.  So long as any Underwriter is required in the
reasonable opinion of Dewey Ballantine to deliver a prospectus, the Guarantor
will not file any amendment to the Registration Statement or supplement to the
Prospectus unless the Guarantor has furnished one copy of such amendment or
supplement to Goldman, Sachs & Co. and to Dewey Ballantine, and, if such
amendment or supplement is to be filed on or prior to the Time of Delivery, or
under circumstances where the Underwriters are required in the reasonable
opinion of Dewey Ballantine, to deliver a Prospectus, the Underwriters or Dewey
Ballantine, shall not reasonably have objected thereto.  If the Commission shall
issue a stop order suspending the effectiveness of the Registration Statement,
the Guarantor will take such steps to obtain the lifting of that order as in the
best judgment of the Guarantor are not contrary to the interests of the
Guarantor;

          (c)  That if, at any time when in the reasonable opinion of Dewey
Ballantine the Prospectus is required by law to be delivered by an Underwriter
or a dealer, any event shall occur as a result of which it is necessary, in the
reasonable opinion of Dewey Ballantine or counsel for the Guarantor, to amend or
supplement the Prospectus or modify the information incorporated by reference
therein in order to make the statements therein, in light of the circumstances
existing when the Prospectus is delivered to a purchaser, not misleading, or if
it shall be necessary in the reasonable opinion of any such counsel, to amend or
supplement the Prospectus or modify such information to comply with law, the
Guarantor will forthwith (i) prepare and furnish, at its own expense, to the
Underwriters and to the dealers (whose names and addresses the Underwriters will
furnish to the Guarantor) to whom Securities may have been sold by the
Underwriters and to any other dealers upon reasonable request, either amendments
or supplements to the Prospectus or (ii) file with the Commission documents
incorporated by reference in the Prospectus, which shall be so supplied to the
Underwriters and such dealers, in either case so that the statements in the
Prospectus as so amended, supplemented or modified will not, in light of the
circumstances when the Prospectus is delivered to a purchaser, be misleading or
so that the Prospectus will comply with law;

          (d)  That the Guarantor will endeavor to qualify, at its expense, the
Securities, and, to the extent required or advisable, the Guarantee and the
Junior Subordinated Notes, for offer and sale under the securities or Blue Sky
laws of such jurisdictions as the Underwriters shall reasonably request and to
pay all filing fees, reasonable expenses and legal fees in connection therewith
and in connection with the determination of the eligibility for investment of
the Securities; provided, that the Guarantor shall not be required to qualify as
                --------                                                        
a foreign corporation or a dealer in securities or to file any consents to
service of process under the laws of any jurisdiction;

          (e)  That the Guarantor will make generally available to its security
holders and the Securityholders as soon as practicable an earnings statement of
the Guarantor covering a twelve-month period beginning after the Time of
Delivery which shall satisfy the provisions of Section 11(a) of the Act and the
rules and regulations of the Commission thereunder (including Rule 158 under the
Act).

                                       8
<PAGE>
 
          (f)  That during the period beginning on the date of this Agreement
and continuing to and including the Time of Delivery, the Guarantor and the
Trust will not offer, sell, contract to sell or otherwise dispose of any
Securities, any security convertible into or exchangeable into or exercisable
for Securities or Subordinated Debentures or any debt securities substantially
similar to the Subordinated Debentures or equity securities substantially
similar to the Securities (except for the Subordinated Debentures and the
Securities issued pursuant to this Agreement), without the prior written consent
of the Underwriters.

          4.   Expenses.  The Guarantor and the Trust jointly and severally
               --------                                                    
covenant and agree with the several Underwriters that the Guarantor and the
Trust will pay or cause to be paid the following: (i) all expenses in connection
with the preparation, printing and filing of the Registration Statement as
originally filed and of each amendment thereto; (ii) the fees, disbursements and
expenses of the Guarantor's or the Trust's counsel and accountants in connection
with the issue of the Securities and all other expenses in connection with the
preparation, printing and filing of the Registration Statement, the Prospectus,
the Preliminary Supplemented Prospectus, the Final Supplemented Prospectus and
any amendments and supplements thereto and the mailing and delivering of copies
thereof to the Underwriters and dealers; (iii) all reasonable expenses in
connection with the qualification of the Securities, the Guarantees and the
Subordinated Debentures issuable upon exchange of the Securities, for offering
and sale under state securities laws as provided in Section 3(d) hereof,
including the reasonable fees and disbursements of counsel for the Underwriters
in connection with such qualification and in connection with the Blue Sky and
legal investment surveys; (iv) any fees charged by securities rating services
for rating the Securities and the Subordinated Debentures; (v) the cost of
preparing the Securities and the Subordinated Debentures; (vi) the fees and
expenses of the Trustees, the Guarantee Trustee and the Debenture Trustee and
any agent of the Trustees, the Guarantee Trustee and the Debenture Trustee and
the fees and disbursements of counsel for the Trustees in connection with the
Trust Agreement and the Securities, counsel for the Guarantee Trustee in
connection with the Guarantee and counsel for the Debenture Trustee in
connection with the Indenture and the Subordinated Debentures; (vii) the fees
and disbursements of Delaware counsel to the Trust; and (viii) all other costs
and expenses incident to the performance of its obligations hereunder which are
not otherwise specifically provided for in this Section.  It is understood,
however, that, except as provided in this Section, and Sections 6 and 9 hereof,
the Underwriters will pay all of their own costs and expenses, including the
fees of their counsel and any advertising expenses connected with any offers
they may make.

          5.   Conditions of Underwriters' Obligations.  The obligations of the
               ---------------------------------------                         
Underwriter hereunder shall be subject to the accuracy, at and (except as
otherwise stated herein) as of the date hereof and at and as of the Time of
Delivery, of the representations and warranties made herein by the Guarantor and
the Trust, to compliance at and as of the Time of Delivery by the Guarantor and
the Trust with their covenants and agreements herein contained and the other
provisions hereof to be satisfied at or prior to the Time of Delivery, and to
the following additional conditions:

          (a)   (i)  No stop order suspending the effectiveness of the
Registration Statement shall be in effect, and no proceeding for such purpose
shall be pending before

                                       9
<PAGE>
 
or threatened by the Commission, and the Underwriters shall have received on and
as of the Time of Delivery, a certificate dated such date, signed by an
executive officer of the Guarantor or an authorized agent of the Guarantor
designated as such by the Board of Directors of the Guarantor to the foregoing
effect, and (ii) there shall have been no material adverse change in or
affecting the business, properties or financial condition of the Guarantor or
the Trust from that set forth in or contemplated by the Registration Statement
at the time it became effective, except as set forth in or contemplated by the
Prospectus, and the Underwriters shall have received on and as of the Time of
Delivery, a certificate dated such date, signed by an executive officer of the
Guarantor or an executive officer of Houston Industries Incorporated ("Houston
Industries") to the foregoing effect. The officers or agents making such
certificates may rely upon the best of his knowledge as to proceedings pending
or threatened.

          (b)  Dewey Ballantine, counsel for the Underwriters, shall have
furnished to you such opinion or opinions, dated the Time of Delivery, with
respect to such matters as you may reasonably request, and such counsel shall
have received such papers and information as they may reasonably request to
enable them to pass upon such matters.  In giving such opinion, such counsel may
rely (i) as to matters of Texas law and the exemption of Houston Industries
under the 1935 Act (as defined herein) upon the opinions of Baker & Botts L.L.P.
referred to in (d) below and Hugh Rice Kelly or such other counsel referred to
in (c) below and (ii) as to matters of Delaware law upon the opinion of
Richards, Layton & Finger referred to in (e) below.

          (c)  Hugh Rice Kelly, Senior Vice President, General Counsel, and
Corporate Secretary for the Guarantor, shall have furnished to you his written
opinion, dated the Time of Delivery, in form and substance satisfactory to you,
to the effect that:

        (i)   The Guarantor has been duly incorporated and is validly existing
              in good standing under the laws of the State of Texas and has
              corporate power and authority to enter into and perform its
              obligations under this Agreement and the Guarantor Agreements;

        (ii)  No consent, approval, authorization or other order of, or
              registration with, any governmental regulatory body (other than
              such as may be required under applicable securities laws, as to
              which such counsel need not express an opinion) is required for
              the issuance and sale of the Securities being delivered at the
              Time of Delivery or the issuance of the Guarantee and the
              Subordinated Debentures or the consummation by the Trust or the
              Guarantor of the transactions contemplated by this Agreement and
              the Guarantor Agreements;

        (iii) To the best of such counsel's knowledge and other than as set
              forth or contemplated in the Prospectus, there are no legal or
              governmental proceedings pending or threatened to which Guarantor
              is subject, which, individually or in the aggregate, are expected
              to have a material adverse effect on the financial position,
              shareholders' equity or results of operations of the Guarantor;

                                       10
<PAGE>
 
        (iv)  The issuance by the Guarantor of the Guarantee and the
              Subordinated Debentures and the execution, delivery and
              performance by the Guarantor of this Agreement and the Guarantor
              Agreements will not result in the breach or violation of, or
              constitute a default under, the Restated Articles of Incorporation
              or the Amended and Restated Bylaws of the Guarantor, each as
              amended to date, any indenture, mortgage, deed of trust or other
              agreement or instrument for borrowed money to which the Guarantor
              is a party or by which it is bound or to which its property is
              subject or any law, order, rule or regulation of any court or
              governmental agency or body having jurisdiction over the Guarantor
              or its property, in any manner which would have a material adverse
              effect on the business of the Guarantor; and

        (v)   The description of statutes and regulations set forth in Part I of
              the Guarantor's Annual Report on Form 10-K for the fiscal year
              ended December 31, 1995 under the captions "Business--Regulatory
              Matters--Rates and Services" and "--Environmental Quality" fairly
              describe in all material respects the portions of the statutes and
              regulations addressed thereby.

         (d)     Baker & Botts L.L.P., counsel for the Guarantor and the Trust,
shall have furnished to you their written opinion, dated the Time of Delivery,
in form and substance satisfactory to you, to the effect that:

         (i)  Such counsel does not know of any contracts or documents of a
              character required to be described in the Registration Statement
              or Prospectus or to be filed as exhibits to the Registration
              Statement which are not so described and filed;


        (ii)  The statements set forth in the Final Supplemental Prospectus
              under the captions "Description of Capital Securities",
              "Description of Junior Subordinated Debentures", "Description of
              Guarantees", "The Expense Agreement" and "Relationship Among the
              Capital Securities, the Corresponding Junior Subordinated
              Debentures, the Expense Agreement and the Guarantees", accurately
              summarize in all material respects the terms of the Securities,
              the Trust Agreement, the Subordinated Debentures, the Expense
              Agreement and the Guarantee, and the statements under the caption
              "Certain ERISA Considerations" insofar as they purport to describe
              the provisions of the laws and regulations referred to therein are
              accurate summaries in all materials respects thereof;

        (iii) The Securities, the Subordinated Debentures and the Guarantee
              conform as to legal matters in all material respects to the
              descriptions thereof contained in the Final Supplemented
              Prospectus under the captions "Certain Terms of Series ___ Capital
              Securities", "Certain Terms of Series ___ Subordinated
              Debentures", and "Certain Terms of Series ___ Guarantee" and in
              the Basic Prospectus under the

                                       11
<PAGE>
 
            captions "Description of Junior Subordinated Debentures",
            "Description of Securities", "Description of Guarantees", and
            "Relationship Among Securities, The Corresponding Junior
            Subordinated Debentures, The Expense Agreement and The Guarantees",
            respectively;


      (v)   The Subordinated Debentures are in the form prescribed in or
            pursuant to the Indenture, have been duly and validly authorized by
            all necessary corporate action on the part of the Guarantor and,
            when executed and delivered by the Guarantor and authenticated by
            the Trustee as specified in or pursuant to the Indenture, will be
            valid and binding obligations of the Guarantor, enforceable in
            accordance with their terms, except as such enforceability is
            subject to the effect of any applicable bankruptcy, insolvency,
            reorganization or other law relating to or affecting creditors'
            rights generally and to general principles of equity (regardless of
            whether such enforceability is considered in a proceeding in equity
            or at law); the Guarantee has been duly and validly authorized by
            all necessary corporate action on the part of the Guarantor; the
            Guarantee has been duly and validly executed and delivered by the
            Guarantor and (assuming due authorization, execution and delivery by
            the Trustee thereunder) constitutes the valid and binding
            obligation of the Guarantor, enforceable in accordance with its
            terms, except as such enforceability is subject to the effect of any
            applicable bankruptcy, insolvency, reorganization or other law
            relating to or affecting creditors' rights generally and to general
            principles of equity (regardless of whether such enforceability is
            considered in a proceeding in equity or at law); the Trust
            Agreement, the Indenture and the Expense Agreement have each been
            duly authorized, executed and delivered by the Guarantor and, when
            executed and delivered by the other parties thereto, will constitute
            valid and binding obligations of the Guarantor, enforceable in
            accordance with their respective terms, except as such
            enforceability is subject to the effect of any applicable
            bankruptcy, insolvency, reorganization or other law relating to or
            affecting creditors' rights generally and to general principles of
            equity (regardless of whether such enforceability is considered in
            proceeding in equity or at law);

      (vi)  The Guarantee, the Trust Agreement and the Indenture have been
            duly qualified under the TIA;

      (vii) Based upon the timely filing by Houston Industries with the
            commission of an exemption statement pursuant to Rule 2 under the
            Public Utility Holding Company Act of 1935 ("1935 Act") which, to
            the best of the knowledge of such counsel, is not the subject of any
            notification provided for in Rule 6 under the 1935 Act, Houston
            Industries is exempt from the provisions of the 1935 Act except
            Sections 9(a)(2), 32 and 33 thereof;

                                       12
<PAGE>
 
          (viii)  The Trust is not and, after giving effect to the offering and
                  sale of the Securities, will not be an "investment company" or
                  an entity "controlled" by an "investment company", as such
                  terms are defined in the Investment Company Act (in giving
                  such opinion counsel may reference specified "no-action" 
                  letters);

            (ix)  The Registration Statement has become effective under the Act,
                  and, to the best of such counsel's knowledge, no stop order
                  suspending the effectiveness of the Registration Statement or
                  any part thereof has been issued and no proceedings for that
                  purpose have been instituted and are pending or are threatened
                  by the Commission under the Act; the Registration Statement,
                  as of its effective date, and the Final Supplemented
                  Prospectus, as of ________ ___, 19__, (except for (A) the
                  operating statistics, financial statements and financial
                  statement schedules contained or incorporated by reference
                  therein or omitted therefrom (including the auditors' reports
                  on the financial statements and the notes to the financial
                  statements), (B) the other financial and statistical
                  information contained or incorporated by reference therein or
                  omitted therefrom and (C) the exhibits thereto, as to which
                  such counsel need not express an opinion) complied as to form
                  in all material respects with the requirements of Form S-3
                  under the Act and the applicable rules and regulations of the
                  Commission thereunder, and each document incorporated by
                  reference therein as originally filed pursuant to the Exchange
                  Act (except for (A) the operating statistics, financial
                  statements and financial statement schedules contained or
                  incorporated by reference therein or omitted therefrom
                  (including the auditors' reports on the financial statements
                  and the notes to the financial statements), (B) the other
                  financial and statistical information contained or
                  incorporated by reference therein or omitted therefrom and (C)
                  the exhibits thereto, as to which such counsel need not
                  express an opinion) when so filed complied as to form in all
                  material respects with the Exchange Act and the applicable
                  rules and regulations of the Commission thereunder; and

             (x)  The execution, delivery and performance by the Guarantor of
                  this Agreement have been duly authorized by all necessary
                  corporate action on the part of the Guarantor, and this
                  Agreement has been duly executed and delivered by the
                  Guarantor.

               In addition, such counsel shall state that no facts have come to
the attention of such counsel that lead them to believe that the Registration
Statement (except for (A) the operating statistics, financial statements and
financial statement schedules contained or incorporated by reference therein
(including the auditors' reports on the financial statements and the notes to
the financial statements, except to the extent that such notes describe legal or
governmental proceedings to which the Company is a party and are incorporated by
reference into one or more items of a report that is incorporated by reference
in the Registration Statement or the Prospectus, other than an item that
requires that financial statements be provided), (B) the other

                                       13
<PAGE>
 
financial and statistical information contained or incorporated by reference
therein and (C) the exhibits thereto, as to which such counsel need not comment)
as of the time such Registration Statement became effective, contained any
untrue statement of a material fact or omitted to state a material fact required
to be stated therein or necessary to make the statements therein not misleading,
or that the Prospectus, as amended, supplemented or modified by the filing of a
document incorporated by reference therein if so amended, supplemented or
modified (except for (A) the operating statistics, financial statement and
financial statements schedules contained or incorporated by reference therein
(including the auditors' reports on the financial statements and the notes to
the financial statements, except to the extent that such notes describe legal or
governmental proceedings to which the Guarantor is a party and are incorporated
by reference into one or more items of a report that is incorporated by
reference in the Prospectus, other than an item that requires that financial
statements be provided), (B) the other financial and statistical information
contained or incorporated by reference therein and (C) the exhibits thereto, as
to which such counsel need not comment), as of the date of the Final
Supplemented Prospectus contained, or as of the Time of Delivery contains, any
untrue statement of a material fact 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.

     (e)  Richards, Layton & Finger, special Delaware counsel for the
Guarantor and the Trust, shall have furnished to you their written opinion,
dated the Time of Delivery, in form and substance satisfactory to you, to the
effect that:

            (i)  The Trust has been duly created and is validly existing in good
                 standing as a business trust under the Delaware Business Trust
                 Act, and all filings required under the laws of the State of
                 Delaware with respect to the creation and valid existence of
                 the Trust as a business trust have been made;

           (ii)  Under the Delaware Business Trust Act and the Trust Agreement,
                 the Trust has the trust power and authority to own property and
                 conduct its business, all as described in the Prospectus;

          (iii)  The Trust Agreement constitutes a valid and legally binding
                 obligation of the Guarantor and the Trustees, and is
                 enforceable against the Guarantor and the Trustees, in
                 accordance with its terms, subject, as to enforcement, to the
                 effect upon the Trust Agreement of (i) bankruptcy, insolvency,
                 fraudulent transfer and conveyance, reorganization, moratorium,
                 receivership, liquidation and similar laws of general
                 applicability relating to or affecting creditors' rights, (ii)
                 principles of equity, including applicable law relating to
                 fiduciary duties, and (iii) the effect of applicable public
                 policy on the enforceability of provisions relating to
                 indemnification or contribution;

           (iv)  Under the Delaware Business Trust Act, the Original Trust
                 Agreement (as defined in the Trust Agreement) and the Trust
                 Agreement, the Trust has the trust power and authority to (a)
                 execute and deliver, and to

                                       14
<PAGE>
 
          perform its obligations under this Agreement and (b) issue and perform
          its obligations under the Securities and the Common Securities;

     (v)  Under the Delaware Business Trust Act, the Original Trust Agreement
          and the Trust Agreement, the execution and delivery by the Trust of
          this Agreement, and the performance by the Trust of its obligations
          hereunder, have been duly authorized by all necessary trust action on
          the part of the Trust;

    (vi)  Under the Delaware Business Trust Act, the Original Trust Agreement
          and the Trust Agreement, this Agreement has been duly executed by the
          Trust;

   (vii)  The Securities have been duly authorized by the Trust Agreement and
          are duly and validly issued and, subject to the qualifications set
          forth herein, fully paid and non-assessable undivided beneficial
          interests in the assets of the Trust and are entitled to the benefits
          provided by the Trust Agreement (subject to the terms of the Trust
          Agreement); provided that such counsel may note that the
          Securityholders may be obligated, pursuant to the Trust Agreement, to
          (a) provide indemnity and/or security in connection with and pay taxes
          or governmental charges arising from transfers or exchanges of Capital
          Securities Certificates and the issuance of replacement Capital
          Securities Certificates and (b) provide security and indemnity in
          connection with requests of or directions to the Property Trustee (as
          defined in the Trust Agreement) to exercise its rights and remedies
          under the Trust Agreement. The Securityholders, as beneficial owners
          of the Trust, are entitled to the same limitation of personal
          liability extended to stockholders of private corporations for profit
          organized under the General Corporation Law of the State of Delaware;

  (viii)  The Common Securities of the Trust have been duly authorized by the
          Trust Agreement and are validly issued, and fully paid undivided
          beneficial interests in the assets of the Trust;

    (ix)  Under the Delaware Business Trust Act and the Trust Agreement, the
          issuance of the Securities and the Common Securities is not subject to
          preemptive rights;

     (x)  The issuance and sale by the Trust of the Securities and the Common
          Securities, the execution, delivery and performance by the Trust of
          this Agreement, the consummation by the Trust of the transactions
          contemplated by this Agreement and the Trust Agreement and compliance
          by the Trust with its obligations thereunder do not violate (a) any of
          the provisions of the Certificate of Trust of the Trust or the Trust
          Agreement, or (b) any applicable Delaware law or administrative
          regulation;

    (xi)  Such counsel has reviewed the statements in the Basic Prospectus under
          the caption "The Issuers" and the statements in the Preliminary
          Supplemented Prospectus and Final Supplemented Prospectus under the
          caption "HL&P Capital Trust ___" and, insofar as they contain
          statements of Delaware law, such statements are fairly presented;

   (xii)  No authorization, approval, consent or order of any Delaware court or
          Delaware governmental authority or Delaware agency is required to be
          obtained

                                       15
<PAGE>
 
             by the Trust solely in connection with the issuance and sale of the
             Securities and the Common Securities. (In rendering the opinion
             expressed in this paragraph (xii), such counsel need express no
             opinion concerning the securities laws of the State of Delaware.);
             and

     (xiii)  Assuming that (i) the Trust derives no income from or connected
             with sources within the State of Delaware and has no assets,
             activities (other than maintaining the Delaware Trustee and the
             filing of documents with the Secretary of State of the State of
             Delaware) or employees in the State of Delaware, and (ii) the Trust
             is treated as a grantor trust for federal income tax purposes, the
             Securityholders (other than those holders of the Securities who
             reside or are domiciled in the State of Delaware) will have no
             liability for income taxes imposed by the State of Delaware solely
             as a result of their participation in the Trust, and the Trust will
             not be liable for any income tax imposed by the State of Delaware.

          (f)   Baker & Botts L.L.P., special tax counsel for the Guarantor and
the Trust, shall have furnished to you their written opinion, dated the Time of
Delivery, in form and substance satisfactory to you, to the effect that such
firm confirms its opinion set forth in the Final Supplemented Prospectus under
the caption "Certain Federal Income Tax Consequences".

          (g)   At the time of execution of this Agreement, Deloitte & Touche
LLP shall have furnished to you a letter dated the date of such execution,
substantially in the form heretofore supplied and deemed satisfactory to you.

          (h)   At the Time of Delivery, Deloitte & Touche LLP shall have
furnished you a letter, dated the Time of Delivery, to the effect that such
accountants reaffirm, as of the Time of Delivery and as though made on the Time
of Delivery, the statements made in the letter furnished by such accountants
pursuant to paragraph (g) of this Section 5, except that the specified date
referred to in such letter will be a date not more than five business days prior
to the Time of Delivery.

          (i)   A Special Event (as defined in the Final Supplemented
Prospectus, except that the reference to effectiveness or announcement on or
after the date of issuance of the Securities shall be deemed a reference to
effectiveness or announcement on or after the date of this Agreement) shall not
have occurred and be continuing.

          (j)   The Guarantor and the Trust shall have furnished or caused to be
furnished to you at the Time of Delivery certificates of officers of the
Guarantor and of administrators of the Trust satisfactory to you as to the
accuracy of the representations and warranties of the Guarantor and the Trust
herein at and as of the Time of Delivery, as to the performance by the Guarantor
and the Trust of all of their respective obligations hereunder to be performed
at or prior to the Time of Delivery, as to the matters set forth in the
introductory paragraph to this Section 5 and subsection (a) of this Section and
as to such other matters as you may reasonably request.

          6.    Indemnification and Contribution.  (a)  The Guarantor and the
                --------------------------------                             
Trust, jointly and severally, agree to indemnify and hold harmless each
Underwriter, and each person, if any, who controls each Underwriter within the
meaning of the Act or the

                                       16
<PAGE>
 
Exchange Act, against any losses, claims, damages, liabilities or expenses
(including the reasonable cost of investigating and defending against any claims
therefore and counsel fees incurred in connection therewith), joint or several,
which may be based upon either the Act, or the Exchange Act, or any other
statute or at common law, on the ground or alleged ground that any Preliminary
Supplemented Prospectus, Final Supplemented Prospectus, Preliminary Prospectus,
the Registration Statement, the Basic Prospectus or the Prospectus (or any such
document, as from time to time amended, or deemed to be amended, supplemented or
modified) includes or allegedly includes an untrue statement of material fact or
omits to state a material fact required to be stated therein or necessary in
order to make the statements therein not misleading, unless such statement or
omission was made in reliance upon, and in conformity with, written information
furnished to the Guarantor or the Trust by any Underwriter through Goldman,
Sachs & Co. specifically for use in the preparation thereof; provided that in no
case is the Guarantor or the Trust to be liable with respect to any claims made
against any Underwriter or any such controlling person unless such Underwriter
or such controlling person shall have notified the Guarantor in writing within a
reasonable time after the summons or other first legal process giving
information of the nature of the claim shall have been served upon such
Underwriter or such controlling person, but failure to notify the Guarantor or
Trust of any such claim shall not relieve it from any liability which it may
have to such Underwriter or such controlling person otherwise than on account of
the indemnity agreement contained in this paragraph; and provided, further, that
the foregoing indemnity with respect to the Preliminary Prospectus, the Basic
Prospectus, the Prospectus, the Preliminary Supplemented Prospectus and the
Final Supplemented Prospectus shall not inure to the benefit of any Underwriter
if a copy of the Preliminary Prospectus, the Basic Prospectus, the Prospectus,
the Preliminary Supplemented Prospectus or the Final Supplemented Prospectus as
amended or supplemented, had not been sent or given by or on behalf of such
Underwriter to the person asserting any such losses, claims, damages or
liabilities concurrently with or prior to delivery of the written confirmation
of the sale of Securities to such person and the untrue statement or omission of
a material fact contained in any such Preliminary Prospectus, Basic Prospectus,
Prospectus, Preliminary Supplemented Prospectus or Final Supplemented Prospectus
was corrected in the Preliminary Prospectus, Basic Prospectus, Prospectus,
Preliminary Supplemented Prospectus or Final Supplemented Prospectus, as amended
or supplemented.

          The Guarantor and the Trust will be entitled to participate at their
own expense in the defense, or, if they so elect, to assume the defense of any
suit brought to enforce any such liability, but, if the Guarantor or the Trust
elects to assume the defense, such defense shall be conducted by counsel chosen
by it.  In the event that the Guarantor or the Trust elects to assume the
defense of any such suit and retains such counsel, the Underwriter or
Underwriters or controlling person or persons, defendant or defendants in the
suit, may retain additional counsel but shall bear the fees and expenses of such
counsel unless (i) the Guarantor or the Trust shall have specifically authorized
the retaining of such counsel or (ii) the parties to such suit include the
Underwriter or Underwriters or controlling person or persons and the Underwriter
or Underwriters or controlling person or persons have been advised by such
counsel that one or more legal defenses may be available to it or them which may
not be available to the Guarantor or the Trust, in which case the Guarantor or
the Trust shall not be entitled to assume the defense of such suit on behalf of
such Underwriter or Underwriters

                                       17
<PAGE>
 
or controlling person or persons, notwithstanding their obligation to bear the
reasonable fees and expenses of such counsel, it being understood, however, that
the Guarantor and the Trust shall not, in connection with any one such suit or
proceeding or separate but substantially similar or related actions or
proceedings 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 at any time for all such Underwriters and their
controlling persons, which firm shall be designated in writing by Goldman, Sachs
& Co.  The Guarantor and the Trust shall not be liable to indemnify any person
for any settlement of any such claim effected without the Guarantor's or the
Trust's consent.  This indemnity agreement will be in addition to any liability
which the Guarantor and the Trust might otherwise have.

          (b)   Each Underwriter agrees to indemnify and hold harmless the
Guarantor and the Trust, each of the Guarantor's directors, each of the
Guarantor's officers who have signed the Registration Statement, each of the
Trustees who have signed the Registration Statement and each person, if any, who
controls the Guarantor and the Trust within the meaning of the Act or the
Exchange Act, against any losses, claims, damages, liabilities or expenses
(including the reasonable cost of investigating and defending against any claims
therefor and counsel fees incurred in connection therewith), joint or several,
which may be based upon the Act, or any other statute or at common law, on the
ground or alleged ground that any Preliminary Supplemented Prospectus, Final
Supplemented Prospectus, Preliminary Prospectus, the Registration Statement, the
Basic Prospectus or the Prospectus (or any such document, as from time to time
amended, or deemed to be amended, supplemented or modified) includes or
allegedly includes an untrue statement of a material fact or omits to state a
material fact required to be stated therein or necessary in order to make the
statements therein not misleading, but only insofar as any such statement or
omission was made in reliance upon, and in conformity with, written information
furnished to the Guarantor or the Trust by such Underwriter through Goldman
Sachs & Co. specifically for use in the preparation thereof; provided that in no
case is such Underwriter to be liable with respect to any claims made against
the Guarantor or the Trust or any such director, officer, trustee or controlling
person unless the Guarantor or the Trust or any such director, officer, trustee
or controlling person shall have notified such Underwriter in writing within a
reasonable time after the summons or other first legal process giving
information of the nature of the claim shall have been served upon the Guarantor
or the Trust or any such director, officer, trustee or controlling person, but
failure to notify such Underwriter of any such claim shall not relieve it from
any liability which it may have to the Guarantor or the Trust or any such
director, officer, trustee or controlling person otherwise than on account of
the indemnity agreement contained in this paragraph. Such Underwriter will be
entitled to participate at its own expense in the defense, or, if it so elects,
to assume the defense of any suit brought to enforce any such liability, but, if
such Underwriter elects to assume the defense, such defense shall be conducted
by counsel chosen by it. In the event that such Underwriter elects to assume the
defense of any such suit and retain such counsel, the Guarantor or the Trust or
any such director, officer, trustee or controlling person, defendant or
defendants in the suit, may retain additional counsel but shall bear the fees
and expenses of such counsel unless (i) such Underwriter shall have specifically
authorized the retaining of such counsel or (ii) the parties to such suit
include the Guarantor or the Trust of any such director, officer, trustee or
controlling person and such Underwriter and the Guarantor or the Trust of such
director, officer, trustee or controlling 

                                      18
<PAGE>
 
person have been advised by such counsel that one or more legal defenses may be
available to it or them which may not be available to such Underwriter, in which
case such Underwriter shall not be entitled to assume the defense of such suit
on behalf of the Guarantor or the Trust of any such director, officer, trustee
or controlling person, notwithstanding its obligation to bear the reasonable
fees and expenses of such counsel, it being understood, however, that such
Underwriter shall not, in connection with any one such suit or proceeding or
separate but substantially similar or related actions or proceedings 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 at any time for all of the Guarantor or the Trust and any such
director, officer, trustee or controlling person, which firm shall be designated
in writing by the Guarantor.  Such Underwriter shall not be liable to indemnify
any person for any settlement of any such claim effected without such
Underwriter's consent.  This indemnity agreement will be in addition to any
liability which such Underwriter might otherwise have.

          (c)   If recovery is not available under Section 6(a) or 6(b) hereof,
for any reason other than as specified therein, the parties entitled to
indemnification by the terms thereof shall be entitled to contribution for
liabilities and expenses, except to the extent that contribution is not
permitted under Section 11(f) of the Act.  In determining the amount of
contribution to which the respective parties are entitled, there shall be
considered the relative benefits received by each party from the offering of the
Securities (taking into account the portion of the proceeds of the offering
realized by each), the parties' relative knowledge and access to information
concerning the matter with respect to which the claim was asserted, the
opportunity to correct and prevent any statement or omission, and any other
equitable considerations appropriate under the circumstances.  The Guarantor and
the Trust and the Underwriters agree that it would not be equitable if the
amount of such contribution were determined by pro rata or per capita allocation
(even if the Underwriters were treated as one entity for such purpose).  No
Underwriters or any person controlling such Underwriters shall be obligated to
make contribution hereunder which in the aggregate exceeds the total public
offering price of the Securities purchased by such Underwriters under this
Agreement, less the aggregate amount of any damages which such Underwriters and
its controlling persons have otherwise been required to pay in respect of the
same claim or any substantially similar claim.  The Underwriters' obligations to
contribute are several in proportion to their respective underwriting
obligations, and not joint.

       7. Substitution of Underwriters.  If any Underwriter shall default in its
          ----------------------------                                      
obligation to purchase the Securities which it has agreed to purchase hereunder
and the aggregate principal amount of such Securities which such defaulting
Underwriter agreed but failed to purchase does not exceed 10% of the aggregate
principal amount of all the Securities, the non-defaulting Underwriters may make
arrangements satisfactory to the Guarantor and Trust for the purchase of the
aggregate principal amount of such Securities by other persons, including the
non-defaulting Underwriters, but if no such arrangements are made prior to the
Time of Delivery, the non-defaulting Underwriters shall be obligated severally
in proportion to their respective commitments hereunder, to purchase the
Securities which such defaulting Underwriter agreed but failed to purchase. If
any Underwriter or Underwriters shall so default and the aggregate principal
amount of such Securities with respect to which such default or defaults occur
is more than 10% of the aggregate principal amount of all the Securities and
arrangements satisfactory to

                                       19
<PAGE>
 
the non-defaulting Underwriters and the Guarantor and the Trust for the purchase
of such Securities by other persons are not made within 48 hours after such
default, this agreement will terminate.

          If the non-defaulting Underwriter or substituted underwriter or
underwriters are required hereby or agree to take up all or part of the
Securities of the defaulting Underwriter as provided in this Section 7, (i) the
Guarantor and the Trust shall have the right to postpone the Time of Delivery
for a period of not more than five full business days, in order that the
Guarantor and the Trust may effect whatever changes may thereby be made
necessary in the Registration Statement or Prospectus or in any other documents
or arrangements, and the Guarantor and the Trust agree to promptly file any
amendments to the Registration Statement or supplements to the Prospectus which
may thereby be made necessary, and (ii) the respective aggregate principal
amount of Securities which the non-defaulting Underwriters or substituted
purchaser or purchasers shall thereafter be obligated to purchase shall be taken
as the basis of their underwriting obligation for all purposes of this
Agreement.  Nothing herein contained shall relieve any defaulting Underwriter of
its liability to the Guarantor and the Trust or the non-defaulting Underwriters
for damages occasioned by its default hereunder.  Any termination of this
Agreement pursuant to this Section 7 shall be without liability on the part of
the non-defaulting Underwriters or the Guarantor or the Trust, other than as
provided in Sections 6 and 9.

          8.   Survival of Indemnities, Representations, Warranties, etc.  The
               ----------------------------------------------------------     
respective indemnities, agreements, representations, warranties and other
statements of the Guarantor and the Trust and the several Underwriters, as set
forth in this Agreement or made by or on behalf of them, respectively, pursuant
to this Agreement, shall remain in full force and effect, regardless of any
investigation (or any statement as to the results thereof) made by or on behalf
of any Underwriter or any controlling person of any Underwriter, or the
Guarantor or the Trust, or any officer or director or controlling person of the
Guarantor or the Trust, and shall survive delivery of and payment for the
Securities.

          9.   Termination.  If this Agreement shall be terminated by the
               -----------                                               
Underwriters, because of any failure or refusal on the part of the Guarantor or
the Trust to comply with the terms or to fulfill any of the conditions of this
Agreement, or if for any reason the Guarantor or the Trust shall be unable to
perform its obligations under this Agreement, the respective indemnities shall
remain in full force and effect and the Guarantor or the Trust will reimburse
the Underwriter or such Underwriters as have so terminated this Agreement with
respect to themselves for all out-of-pocket expenses (including the fees and
disbursements of their counsel) reasonably incurred by them in connection with
the transactions contemplated by this Agreement.

          10.  Notices.  In all dealings hereunder, you shall act on behalf of
               -------                                                        
each of the Underwriters, and the parties hereto shall be entitled to act and
rely upon any statement, request, notice or agreement on behalf of any
Underwriter made or given by you.

          All statements, requests, notices and agreements hereunder shall be in
writing, and (i) if to the Underwriters shall be delivered or sent by mail,
telex or facsimile

                                       20
<PAGE>
 
transmission to you in care of Goldman, Sachs & Co., 85 Broad Street, New York,
New York 10004, Attention: Registration Department; (ii) if to the Guarantor
shall be delivered or sent by mail, telex or facsimile transmission to the
Guarantor in care of Houston Industries Incorporated, 1111 Louisiana, Houston,
Texas 77002, Attention, Assistant Treasurer; and (iii) if to the Trust shall be
delivered or sent by mail, telex or facsimile transmission to the Trust, 200
West 9th Street Plaza, Box 2105, Wilmington, Delaware 19899. Any such
statements, requests, notices or agreements shall take effect upon receipt
thereof.

          11.  Successors.  This Agreement shall inure to the benefit of and be
               ----------                                                      
binding upon the several Underwriters, the Guarantor and the Trust and their
respective successors and the directors, trustees, officers and controlling
persons referred to in Section 6 of this Agreement. Nothing expressed or
mentioned in this Agreement is intended or shall be construed to give any person
other than the persons mentioned in the preceding sentence any legal or
equitable right, remedy or claim under or in respect of this Agreement, or any
provisions herein contained; this Agreement and all conditions and provisions
hereof being intended to be, and being, for the sole and exclusive benefit of
such persons and for the benefit of no other person; except that the
representations, warranties, covenants, agreements and indemnities of the
Guarantor and the Trust contained in this Agreement shall also be for the
benefit of the person or persons, if any, who control any Underwriter within the
meaning of the Act or the Exchange Act, and the representations, warranties,
covenants, agreements and indemnities of the several Underwriters shall also be
for the benefit of each Trustee, each director of the Guarantor, each person who
has signed the Registration Statement and the person or persons, if any, who
control the Guarantor and the Trust within the meaning of the Act.

          12.  Applicable Law.  This Agreement shall be governed by and
               --------------                                          
construed in accordance with the laws of the State of New York.

          13.  Counterparts.  This Agreement may be executed by any one or more
               ------------                                                    
of the parties hereto in any number of counterparts, each of which shall be
deemed to be an original, but all such respective counterparts shall together
constitute one and the same instrument.

                                       21
<PAGE>
 
          If the foregoing is in accordance with your understanding, please sign
and return to us seven counterparts hereof, and upon the acceptance hereof by
you, on behalf of each of the Underwriters, this letter and such acceptance
hereof shall constitute a binding agreement between each of the Underwriters and
the Guarantor and the Trust. It is understood that your acceptance of this
letter on behalf of each of the Underwriters is pursuant to the authority set
forth in a form of Agreement among Underwriters, the form of which shall be
submitted to the Guarantor and the Trust for examination upon request, but
without warranty on your part as to the authority of the signers thereof.

                    Very truly yours,


                    HL&P Capital Trust ___
                    By: Houston Lighting & Power Company, as Depositor



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


                    Houston Lighting & Power Company



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



Accepted as of the date hereof:
Goldman, Sachs & Co.
Merrill Lynch, Pierce, Fenner
 & Smith Incorporated



By: 
    ---------------------------
      (Goldman, Sachs & Co.)

     On behalf of each of the Underwriters

                                       22
<PAGE>
 
                                  SCHEDULE I

                                                                    Liquidation
                                                                     Amount of
                                                                     Securities
                                                                       to be
                         Underwriters                                Purchased
                         ------------                                ---------
Goldman, Sachs & Co. ...........................................   $
Merrill Lynch, Pierce, Fenner & Smith Incorporated..............
          Total.................................................  [$           ]

                                       23