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                          OYSTER CREEK AGREEMENT
  
     This Oyster Creek Agreement (this "Agreement"), effective as of February 
17, 1997, is by and among Destec Energy, Inc. ("Destec"), a Delaware 
corporation, The Dow Chemical Company ("Dow"), a Delaware corporation and NGC 
Corporation ("NGC"), a Delaware corporation.

                                WITNESSETH:
                                -----------

            WHEREAS, Oyster Creek Limited (the "Partnership"), a Texas 
limited partnership, which was formed pursuant to an Agreement of Limited 
Partnership, dated May 28, 1991, as amended and restated by the Amended and 
Restated Agreement of Limited Partnership (the "Restated Partnership 
Agreement"), dated September 9, 1992, by and among OCG CoGen, Inc. ("DGP"), a 
Delaware corporation, Oyster Creek CoGen ("DLP"), a Delaware corporation 
(collectively referred to in this Agreement as the "Destec Partners"), 
Transco Oyster Creek Company, a Delaware corporation and TEVCO Cogeneration 
Company, a Delaware corporation, has entered into that certain Ground Lease 
and Agreement (the "Ground Lease"), dated as of August 31, 1992, by and 
between Dow and the Partnership; and

     WHEREAS, pursuant to the Ground Lease the Partnership has constructed a 
cogeneration facility upon certain leased premises located within Dow's 
manufacturing complex at or near Oyster Creek, Texas (the "Project"); and

     WHEREAS, DGP and DLP are each a wholly owned subsidiary of Destec, the 
majority of the voting securities of which are owned by Dow; and
  
     WHEREAS, NGC desires to acquire Destec pursuant to an Agreement and Plan 
of Merger, dated February 17, 1997, by and among Destec, Dow, NGC and NGC 
Acquisition Corporation II (the "Acquisition"); and

     WHEREAS, pursuant to an Option Agreement, dated August 31, 1992 (the 
"Original Option Agreement"), DGP and DLP granted Dow various rights, 
including without limitation, an option to purchase, on the terms and 
conditions set forth therein, the partnership interests of DGP and DLP (the 
"Original Option"), as such interests are restated pursuant to the Restated 
Partnership Agreement (the "Subject Interests"); and

     WHEREAS, pursuant to the Original Option Agreement, upon the 
consummation of the Acquisition, Dow has the right to exercise the Original 
Option and purchase from DGP and DLP the Subject Interests; and

     WHEREAS, in order to induce Dow to waive its right 

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to exercise the Original Option upon the consummation of the Acquisition, the 
parties are entering into this Agreement;

     NOW, THEREFORE, in consideration of the mutual covenants and agreements 
set forth in this Agreement, the receipt and sufficiency of which are 
mutually acknowledged, the parties agree as follows:

     1.   Upon the consummation of the Acquisition, Dow hereby waives its 
right to exercise its option under Section 1(a) of the Original Option 
Agreement (but no other rights under the Original Option Agreement).

     2.   NGC and Destec agree that, from and after the closing of the 
Acquisition, Destec shall not, directly or indirectly, sell or transfer any 
or all of the stock of the Destec Partners (the "Partners Stock") other than 
to an affiliate of Destec (which shall then be bound by this Agreement) 
unless Destec has given Dow a right of first refusal with respect to the 
Partners Stock on the following terms:
  
          (a)  Prior to presenting Dow with a specific proposal from a party 
not affiliated with Destec to purchase the Partners Stock, Destec shall give 
Dow at least 14 days written notice that Destec is considering a sale of the 
Partners Stock and the identity and address of the prospective buyer or 
buyers (collectively referred to as, the "Prospective Buyer").  The 
Prospective Buyer must have sufficient financial resources to consummate a 
transaction.
  
          (b)  At any time after the period described in subparagraph (a), if 
Destec has received a bona fide written proposal to purchase the Partners 
Stock which is not subject to financing conditions from a Prospective Buyer 
which Destec wishes to accept, Destec shall furnish Dow with a copy of such 
proposal and shall offer to sell the Partners Stock to Dow on substantially 
the same terms and conditions as set forth in such proposal. Destec's offer 
to sell the Partners Stock to Dow is referred to herein as the "Offer".  Dow 
shall then have 14 days in which to decide to accept such Offer.  If Dow does 
not accept such Offer within that 14-day period, Destec shall have the right, 
for the next 90 days, to sell the Partners Stock to the Prospective Buyer on 
terms no more favorable to the Prospective Buyer than those set forth in the 
Offer.
  
          (c)  Destec shall not present Dow with more than two Offers in any 
12-month period.
  
     3.   Any notice, request, or other communication given or made pursuant 
to this Agreement shall be effective when received and shall be in writing 
and shall be hand delivered or sent by mail, courier, or facsimile or other 
electronic communication, addressed as follows:

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                 NGC
  
                      NGC Corporation
                      13430 Northwest Freeway, Suite 1200
                      Houston, Texas 77040-6095
                      Attention:  General Counsel
                      Facsimile:  (713) 507-6808
  
                 DESTEC 
                      2500 CityWest Blvd., Suite 150
                      Houston, Texas  77042
                      Attention:  General Counsel
                      Facsimile:  (713) 735-4267
  
                 THE DOW CHEMICAL COMPANY
  
                      Texas Operations - Legal Department
                      APB Building
                      2301 Brazosport Boulevard
                      Freeport, Texas  77541-3257
                      Attention:  Division Counsel
                      Facsimile:  (409) 238-3587
  
or in each case to such other person or address or addresses as one party may 
notify in writing to the other.
  
     4.   The parties to this Agreement agree that Section 13.1(b) of the 
Restated Partnership Agreement shall not be amended without the prior written 
consent of Dow.
  
     5.   This Agreement shall not be construed to modify or eliminate rights 
of the parties contained in other agreements, including without limitation 
the Ground Lease or the Original Option (other than Dow's rights to exercise 
its option under Section 1(a) of the Original Option Agreement upon the 
consummation of the Acquisition).

     IN WITNESS WHEREOF, the parties to this Agreement have executed multiple 
copies of this Oyster Creek Agreement to be effective as of the date first 
above written.
  
THE DOW CHEMICAL COMPANY
  
By: /s/ B.G. Taylorson          
   ------------------------------ 
   Name:  B.G. Taylorson          
   Title: Corporate Director,     
          Mergers & Acquisitions  
  
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DESTEC ENERGY, INC.
  
By:                               

   /s/ Enrique M. Larroucau    
   ------------------------------ 
   Name:  Enrique M. Larroucau    
   Title: Senior Vice President,  
          Chief Financial Officer 
          and Treasurer           
  
  
NGC CORPORATION
  
By: /s/ Kenneth E. Randolph
   ------------------------------ 
   Name: Kenneth E. Randolph
         -------------------      
   Title: Senior Vice President 
          and General Counsel
         -------------------