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                                                                     EXHIBIT 4d3

                         SECOND SUPPLEMENTAL INDENTURE


         This Second Supplemental Indenture, dated as of August 6, 1997 (this
"Second Supplemental Indenture"), among Houston Lighting & Power Company, a
Texas corporation ("HL&P"), HI Merger, Inc., a Delaware corporation ("HI
Merger"), NorAm Energy Corp., a Delaware corporation (the "Company"), and The
Bank of New York, as Trustee (the "Trustee"), supplements the Indenture dated
as of June 15, 1996 (the "Indenture") between the Company and the Trustee, as
supplemented by the First Supplemental Indenture dated as of June 15, 1996
("First Supplemental Indenture") between the Company and the Trustee under
which the Company's 6 1/4% Convertible Junior Subordinated Debentures (the
"Debentures") were issued and are outstanding.

                                    RECITALS

                 WHEREAS, pursuant to the terms of the Indenture the Debentures
were convertible into shares of common stock, par value $.625 per share ("NorAm
Common Stock"), of the Company prior to the Effective Time (as defined below);

                 WHEREAS, pursuant to an Agreement and Plan of Merger dated as
of August 11, 1996, as amended by the Amendment to Agreement and Plan of Merger
dated as of October 23, 1996 (the "Merger Agreement"), among Houston Industries
Incorporated, a Texas corporation ("HI"), HL&P, HI Merger and the Company, HI
will be merged with and into HL&P, with HL&P to be the surviving corporation
and renamed "Houston Industries Incorporated" ("Houston"), and the Company will
be merged with and into HI Merger (the "NorAm Merger"), with HI Merger to be
the surviving corporation and renamed "NorAm Energy Corp.," as a result of
which each outstanding share of NorAm Common Stock will be converted into
either cash or shares of common stock, no par value, of Houston ("Houston
Common Stock"), as set forth in the Merger Agreement.  The cash amount per
share of NorAm Common Stock will be $16.00 plus two percent (simple interest)
per quarter from May 11, 1997 until the closing of the NorAm Merger (the "Cash
Consideration").  The number of shares of Houston Common Stock issued per share
of NorAm Common Stock will be not less than 0.6154 shares nor more than 0.7529
shares (the "Stock Consideration").  The actual number will depend upon the
average closing price of HI common stock on the New York Stock Exchange during
a 20-trading-day period commencing 25 trading days prior to the closing date of
the NorAm Merger.  The Merger Agreement contains certain provisions generally
designed to result in 50% of the outstanding shares of NorAm Common Stock being
converted into the Cash Consideration and 50% of the outstanding shares of
NorAm Common Stock being converted into the Stock Consideration;

                 WHEREAS, in connection with the NorAm Merger, HL&P, the
Company and HI Merger have duly determined to make, execute and deliver to the
Trustee this Second Supplemental Indenture in order to reflect the results of
the NorAm Merger as required by the Indenture;
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                 WHEREAS, pursuant to Section 10.1 of the Indenture, HI Merger,
as the surviving corporation of the NorAm Merger, is required to expressly
assume, by an indenture supplemental to the Indenture, the due and punctual
payment of the principal of (and premium, if any) and interest on all the
Debentures in accordance with the terms of the Debentures, according to their
tenor and the due and punctual performance of all covenants and conditions of
the Indenture on the part of the Company to be performed or observed and to
provide for the conversion rights of Holders of Debentures in accordance with
Section 7.4 of the First Supplemental Indenture;

                 WHEREAS, Section 7.4 of the First Supplemental Indenture
requires that, as a result of the NorAm Merger, a Holder of a Debenture shall
have the right to convert the Debenture into the consideration receivable upon
the NorAm Merger by a holder of shares of NorAm Common Stock into which the
Debenture could have been converted immediately prior to the NorAm Merger;

                 WHEREAS, Section 2.2(f) of the Merger Agreement provides that
following the effective time of the NorAm Merger (the "Effective Time"), each
outstanding Debenture will be convertible into the amount of Stock
Consideration (and cash in lieu of fractional shares of Houston Common Stock)
and Cash Consideration which the Holder thereof would have had the right to
receive after the Effective Time if such Debenture had been converted
immediately prior to the Effective Time and the Holder thereof had made the
Stock Election (as defined in the Merger Agreement) and received the Stock
Consideration with respect to 50% of the shares of NorAm Common Stock issuable
upon such conversion of the Holder's Debentures and made the Cash Election (as
defined in the Merger Agreement) and received the Cash Consideration with
respect to the remaining 50% of such NorAm Common Stock; and

                 WHEREAS, Section 9.1 of the indenture provides that under
certain conditions the Company and the Trustee, without the consent of the
Holders of Debentures, from time to time and at any time, may enter into an
indenture supplemental to the Indenture, inter alia, to evidence the succession
of another corporation to the Company and the assumption by any such successor
of the covenants of the Company under the Indenture, as supplemented by the
First Supplemental Indenture, and in the Debentures;

                 NOW, THEREFORE, THIS SECOND SUPPLEMENTAL INDENTURE WITNESSETH:

         In consideration of the premises and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged,
and to comply with Sections 9.1 and 10.1 of the Indenture and Section 7.4 of
the First Supplemental Indenture, the parties hereto hereby agree, for the
equal and proportionate benefit of the respective Holders from time to time of
the Debentures, as follows:

         Section 1.    Defined Terms.  Capitalized terms used and not otherwise
defined herein have the respective meanings assigned to such terms in the
Indenture and the First Supplemental Indenture.





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         Section 2.    Succession by Merger.

         (1)     As of the Effective Time, HI Merger shall become the successor
to the Company for all purposes of the Indenture, as supplemented by the First
Supplemental Indenture and HI Merger hereby expressly assumes the due and
punctual payment of the principal of (and premium, if any) and interest on all
the Debentures and the performance of every covenant of the Indenture, as
supplemented by the First Supplemental Indenture and by this Second
Supplemental Indenture, on the part of the Company to be performed or observed.

         (2)     Concurrently with the execution and delivery of this Second
Supplemental Indenture, the Company has delivered to the Trustee an Officers'
Certificate and an Opinion of Counsel as required by Sections 9.5 and 13.7 of
the Indenture.

         Section 3.    Conversion Privilege.  The Holder of each Debenture
outstanding as of the Effective Time (and each subsequent Holder) shall have
the right from and after the Effective Time to convert such Debenture only into
the amount, subject to the adjustments provided for in Article Seven of the
First Supplemental Indenture, of Stock Consideration (and cash in lieu of
fractional shares of Houston Common Stock) and Cash Consideration which the
Holder thereof would have had the right to receive after the Effective Time if
such Debenture had been converted immediately prior to the Effective Time and
the Holder thereof had made the Stock Election (as defined in the Merger
Agreement) and received the Stock Consideration with respect to 50% of the
shares of NorAm Common Stock issuable upon such conversion of the Holder's
Debentures and made the Cash Election (as defined in the Merger Agreement) and
received the Cash Consideration with respect to the remaining 50% of such NorAm
Common Stock.

         Section 4.    Additional Covenants of Houston.  HL&P hereby (i) agrees
to (A) reserve and keep available out of its authorized but unissued capital
stock, solely for the purpose of issuance upon the conversion of Debentures as
provided in this Second Supplemental Indenture and the First Supplemental
Indenture, a number of shares of Houston Common Stock sufficient to issue the
Stock Consideration upon the conversion of all outstanding Debentures and (B)
issue and cause to be delivered in accordance with this Second Supplemental
Indenture, the First Supplemental Indenture and the Company's instructions, the
Stock Consideration and the Cash Consideration upon conversion of any Debenture
and (ii) warrants that all shares of Houston Common Stock that may be issued
upon the conversion of any Debenture, when so issued, shall be duly authorized,
validly issued, fully paid and nonassessable.

         Section 5.    Ratification.  The Indenture, as supplemented by the
First Supplemental Indenture, and as hereby supplemented is in all respects
ratified and confirmed by each of the parties hereto, and all of the rights and
powers created thereby or thereunder shall be and remain in full force and
effect.

         Section 6.    Governing Law.  The laws of the State of New York shall
govern this Second Supplemental Indenture without regard to principles of
conflict of laws.





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         Section 7.    Successors.  All agreements of the parties hereto in
this Second Supplemental Indenture shall bind their respective successors.

         Section 8.    Multiple Counterparts.  The parties hereto may sign
multiple counterparts of this Second Supplemental Indenture.  Each signed
counterpart shall be deemed an original, but all of them together represent the
same agreement.





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         IN WITNESS WHEREOF, the undersigned have caused this Second
Supplemental Indenture to be executed by its duly authorized officer as of the
date first above written.


                                      HOUSTON LIGHTING & POWER COMPANY


                                      By: /s/ HUGH RICE KELLY
                                         ---------------------------------
                                         Name:  Hugh Rice Kelly
                                         Title: Executive Vice President, 
                                                General Counsel
                                                and Corporate Secretary

Attest:


By:  /s/ RUFUS S. SCOTT
   ---------------------------------
   Name:  Rufus S. Scott
   Title: Assistant Corporate Secretary


                                      HI MERGER, INC.


                                      By:  STEPHEN W. NAEVE
                                         ---------------------------------
                                         Name:  Stephen W. Naeve
                                         Title: President

Attest:


By:  /s/ RICHARD B. DAUPHIN
   ---------------------------------
   Name:  Richard B. Dauphin
   Title: Assistant Corporate Secretary





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                                      NORAM ENERGY CORP.


                                      By:  /s/ T. MILTON HONEA
                                         ---------------------------------
                                         Name:  T. Milton Honea
                                         Title: President

Attest:


By:  /s/ HUBERT GENTRY, JR.
   ---------------------------------
   Name:  Hubert Gentry, Jr.
   Title: Secretary

                                      THE BANK OF NEW YORK
                                      Trustee


                                      By:  /s/ PAUL J. SCHMALZEL
                                         ---------------------------------
                                         Name:  Paul J. Schmalzel
                                         Title: Assistant Vice President

Attest:


By:  /s/ VIVIAN GEORGES
   ---------------------------------
   Name:  Vivian Georges
   Title: Assistant Vice President





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