EXHIBIT 5.1

                        [BAKER BOTTS L.L.P. LETTERHEAD]


May 18, 2006

064363.0189

CenterPoint Energy Resources Corp.
1111 Louisiana
Houston, Texas  77002

Ladies and Gentlemen:

      In connection with the issuance by CenterPoint Energy Resources Corp., a
Delaware corporation (the "Company"), of $325,000,000 aggregate principal amount
of its 6.15% Senior Notes due 2016 (the "Notes") pursuant to (a) the Company's
Registration Statement on Form S-3 (Registration No. 333-128187) (the
"Registration Statement"), which was filed by the Company with the Securities
and Exchange Commission (the "Commission") under the Securities Act of 1933, as
amended (the "Act"), and (b) the related prospectus dated September 14, 2005, as
supplemented by the prospectus supplement relating to the sale of the Notes
dated May 15, 2006 (as so supplemented, the "Prospectus"), as filed by the
Company with the Commission pursuant to Rule 424(b) under the Act, certain legal
matters with respect to the Notes are being passed upon for you by us. At your
request, this opinion is being furnished to you for filing as Exhibit 5.1 to the
Company's Current Report on Form 8-K to be filed with the Commission on the date
hereof (the "Form 8-K").

      The Notes are to be issued pursuant to an Indenture, dated as of
February 1, 1998, as heretofore supplemented and amended (the "Base Indenture"),
between the Company, formerly known as NorAm Energy Corp., and JPMorgan Chase
Bank, National Association (successor to Chase Bank of Texas, National
Association), as trustee (the "Trustee"), as supplemented by Supplemental
Indenture No. 9 thereto, dated as of May 18, 2006 (the "Supplemental Indenture,"
and together with the Base Indenture, the "Indenture"), between the Company and
the Trustee. The terms of the Notes (including the form of Note) are established
by the Supplemental Indenture.

      In our capacity as your counsel in the connection referred to above, we
have examined originals, or copies certified or otherwise identified, of (i) the
Company's Certificate of Incorporation and By-laws, in each case as amended to
date; (ii) the Underwriting Agreement dated May 15, 2006 (the "Underwriting
Agreement") by and among the Company and the Underwriters named in Schedule I
thereto (the "Underwriters"), relating to the issuance and sale of the Notes;
(iii) the Registration Statement and the Prospectus; (iv) the Indenture; and (v)
the corporate records of the Company as furnished to us by you, certificates of
public officials and of representatives of Company, statutes and other
instruments and documents as a basis for the opinions hereinafter expressed. In
giving such opinions, we have relied upon certificates of officers of the
Company and of public officials with respect to the accuracy of the material
factual matters contained in such certificates. In giving the opinions below, we
have assumed that the signatures on all documents examined by us are genuine,
that all documents submitted to

BAKER BOTTS L.L.P.
CenterPoint Energy Resources Corp.      2                           May 18, 2006


us as originals are accurate and complete, that all documents submitted to us as
copies are true and correct copies of the originals thereof and that all
information submitted to us was accurate and complete.

      On the basis of the foregoing, and subject to the assumptions, limitations
and qualifications hereinafter set forth, we are of the opinion that the Notes
will, when duly executed, issued and delivered by the Company, authenticated and
delivered by the Trustee in accordance with the terms of the Indenture and duly
purchased and paid for by the Underwriters in accordance with the terms of the
Underwriting Agreement, constitute legal, valid and binding obligations of the
Company, enforceable against the Company in accordance with their terms, except
as that enforcement is subject to any applicable bankruptcy, insolvency,
reorganization, moratorium, fraudulent transfer or conveyance or other laws
relating to or affecting creditors' rights generally, and general principles of
equity (regardless of whether that enforceability is considered in a proceeding
in equity or at law).

      The opinions set forth above are limited in all respects to matters of the
contract law of the State of New York, the General Corporation Law of the State
of Delaware and applicable federal law. We hereby consent to the filing of this
opinion of counsel as Exhibit 5.1 to the Form 8-K. We also consent to the
reference to our Firm under the heading "Legal Matters" in the Prospectus. In
giving this consent, we do not hereby admit that we are in the category of
persons whose consent is required under Section 7 of the Act or the rules and
regulations of the Commission thereunder.

                                    Very truly yours,


                                    /s/ BAKER BOTTS L.L.P.