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                                                                    Exhibit 4.12
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                               NGC CORPORATION,

                              DESTEC ENERGY, INC.


                                      AND


                      THE FIRST NATIONAL BANK OF CHICAGO

                                    TRUSTEE


                                _______________


                         FOURTH SUPPLEMENTAL INDENTURE

                           Dated as of June 30, 1997


                               ________________



                   Supplementing and Amending the Indenture
                                  dated as of
                               December 11, 1995


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     THIS FOURTH SUPPLEMENTAL INDENTURE, dated as of June 30, 1997, is among NGC
Corporation, a corporation duly organized and existing under the laws of the
State of Delaware (herein called the "Company"), having its principal office at
1000 Louisiana, Suite 5800, Houston, Texas 77002, Destec Energy, Inc., a
Delaware corporation ("Destec"), and The First National Bank of Chicago, a
national banking association, as Trustee (herein called the "Trustee").  Any
capitalized term used in this Fourth Supplemental Indenture and not defined
herein shall have the meaning specified in the Indenture (as defined below).

                            RECITALS OF THE COMPANY

     The Company and each of the Initial Subsidiary Guarantors heretofore have
made, executed and delivered to the Trustee an Indenture dated as of December
11, 1995 (the "Original Indenture") to provide for the issuance from time to
time of unsecured debentures, notes or other evidences of indebtedness of the
Company (herein called the "Securities"), to be issued in one or more series as
provided in the Original Indenture.

     The Company's obligations under the Original Indenture and the Securities
are guaranteed by the Subsidiary Guarantors.

     The Company has duly authorized and issued a series of $150,000,000
aggregate principal amount of its 6 3/4% Senior Notes due December 15, 2005 (the
"Notes") as Securities pursuant to the Original Indenture.

     Pursuant to a First Supplemental Indenture dated as of August 31, 1996 (the
"First Supplemental Indenture"), (i) Warren Petroleum Company, Limited
Partnership, a Delaware limited partnership ("Warren Petroleum"), (ii) WPC LP,
Inc., a Delaware corporation, and (iii) WTLPS, Inc., a Delaware corporation,
each became an Additional Subsidiary Guarantor.

     Pursuant to a Second Supplemental Indenture dated as of October 11, 1996
(the "Second Supplemental Indenture"), Electric Clearinghouse, Inc. became an
Additional Subsidiary Guarantor.

     Pursuant to a Third Supplemental Indenture dated as of April 23, 1997 (the
"Third Supplemental Indenture"),  (i) Warren Petroleum was reclassified as an
Initial Subsidiary Guarantor rather than an Additional Subsidiary Guarantor,
(ii) Warren Energy Resources, Limited Partnership, Warren Gas Marketing, Inc.,
Warren NGL Pipeline Company, Kansas Gas Supply Corporation, Warren Intrastate
Gas Supply, Inc., NGC Great Britain Limited, NGC Canada, Inc. and NGC Futures,
Inc. were each reclassified as Additional Subsidiary Guarantors rather than
Initial Subsidiary Guarantors and (iii) NGC Storage, Inc., HUB Services, Inc.
and NGC Anadarko Gathering Systems, Inc. were permanently released as guarantors
of the Securities.  In addition, the names of certain Subsidiary Guarantors were
changed in the Third Supplemental Indenture.

     Destec will become a guarantor of certain Funded Indebtedness of the
Company.

     Section 1505 of the Original Indenture provides that if any Subsidiary of
the Company guarantees or becomes primarily obligated with respect to any Funded
Indebtedness of the Company other than the Securities at any time subsequent to
the Issue Date, then the Company shall cause the Securities to be equally and
ratably guaranteed by such Subsidiary and cause such Subsidiary to 
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execute and deliver a supplemental indenture evidencing its provision of a
Subsidiary Guarantee in accordance with the terms of the Original Indenture.

     It is deemed necessary and desirable to supplement and amend the Original
Indenture to add Destec as a Subsidiary Guarantor as provided in Section 1505 of
the Original Indenture (the Original Indenture, as so supplemented and amended
by the First Supplemental Indenture, the Second Supplemental Indenture, the
Third Supplemental Indenture and this Fourth Supplemental Indenture, being
sometimes referred to herein as the "Indenture").

     The Company has delivered to the Trustee an Officers' Certificate and an
Opinion of Counsel, stating that this Fourth Supplemental Indenture has been
duly authorized and executed by Destec and constitutes the legal, valid, binding
and enforceable obligation of Destec subject to certain exceptions regarding
enforceability.

     All things necessary to make this Fourth Supplemental Indenture and the
Original Indenture a valid agreement of the Company and each of the Subsidiary
Guarantors, in accordance with its terms, have been done.


     NOW, THEREFORE, THIS INDENTURE WITNESSETH:

     For and in consideration of the premises and the purchase of the Securities
(together with the related Subsidiary Guarantees) by the Holders thereof, it is
mutually agreed, for the equal and proportionate benefit of all Holders of the
Securities or of a series thereof (together with the related Subsidiary
Guarantees), as follows:

                                  ARTICLE ONE

                        ADDITIONAL SUBSIDIARY GUARANTOR

     SECTION 1.1.   ADDITION OF DESTEC AS A SUBSIDIARY GUARANTOR.  Destec by
execution of this Fourth Supplemental Indenture hereby agrees to be bound by the
terms of the Indenture as a Subsidiary Guarantor and agrees to be subject to the
provisions (including the representations and warranties) of the Indenture
applicable to Subsidiary Guarantors.

                                  ARTICLE TWO

                         ADDITIONAL REPRESENTATIONS AND
                      COVENANTS OF THE COMPANY AND DESTEC

     SECTION 2.1    AUTHORITY OF THE COMPANY.  The Company represents and
warrants that it is duly authorized by a resolution of its Board of Directors to
execute and deliver this Fourth Supplemental Indenture, and all corporate action
on its part required for the execution and delivery of this Fourth Supplemental
Indenture has been duly and effectively taken.

     SECTION 2.2    AUTHORITY OF DESTEC.  Destec represents and warrants that it
is duly authorized by a resolution of its Board of Directors to execute and
deliver this Fourth Supplemental Indenture, 


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and all corporate action on its part required for the execution and delivery of
this Fourth Supplemental Indenture has been duly and effectively taken.

     SECTION 2.3    RECITALS AND STATEMENTS.  The Company warrants that the
recitals of fact and statements contained in this Fourth Supplemental Indenture
are true and correct, and that the recitals of fact and statements contained in
all certificates and other documents furnished hereunder will be true and
correct.

                                 ARTICLE THREE

                             CONCERNING THE TRUSTEE

     SECTION 3.1    ACCEPTANCE OF TRUSTS.  The Trustee accepts the trust
hereunder and agrees to perform the same, but only upon the terms and conditions
set forth in the Indenture, to all of which the Company, the Subsidiary
Guarantors and the respective Holders of Securities at any time hereafter
outstanding agree by their acceptance thereof.

     SECTION 3.2    RESPONSIBILITY OF TRUSTEE FOR RECITALS, ETC.  The recitals
and statements contained in this Fourth Supplemental Indenture shall be taken as
the recitals and statements of the Company, and the Trustee assumes no
responsibility for the correctness of the same.  The Trustee makes no
representations as to the validity or sufficiency of this Fourth Supplemental
Indenture, except that the Trustee is duly authorized to execute and deliver
this Fourth Supplemental Indenture.


                                  ARTICLE FOUR

                            MISCELLANEOUS PROVISIONS

     SECTION 4.1    RELATION TO THE INDENTURE.  The provisions of this Fourth
Supplemental Indenture shall be deemed to be effective immediately upon the
execution and delivery hereof. This Fourth Supplemental Indenture and all the
terms and provisions herein contained shall form a part of the Indenture as
fully and with the same effect as if all such terms and provisions had been set
forth in the Original Indenture.  The Original Indenture is hereby ratified and
confirmed and shall remain and continue in full force and effect in accordance
with the terms and provision thereof, as supplemented and amended by the First
Supplemental Indenture, the Second Supplemental Indenture, the Third
Supplemental Indenture and this Fourth Supplemental Indenture. The Original
Indenture as so supplemented shall be read, taken and construed together as one
instrument.

     SECTION 4.2    COUNTERPARTS OF FOURTH SUPPLEMENTAL INDENTURE.  This Fourth
Supplemental Indenture may be executed in any number of counterparts, each of
which so executed shall be deemed to be an original, but all such counterparts
shall together constitute but one and the same instrument.

     SECTION 4.3    GOVERNING LAW.  This Fourth Supplemental Indenture shall be
governed by and construed in accordance with the laws of the State of New York.


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     IN WITNESS WHEREOF, the parties hereto have caused this Fourth Supplemental
Indenture to be effective, all as of the day and year first above written.

                              COMPANY

                              NGC CORPORATION


                              By__________________________________
                                    Name:
                                    Title:


                              ADDITIONAL SUBSIDIARY GUARANTOR


                              DESTEC ENERGY, INC.


                              By____________________________________
                                    Name:
                                    Title:

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                              TRUSTEE

                              THE FIRST NATIONAL BANK OF CHICAGO


                              By_____________________________________
                                    Name:
                                    Title:


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