<PAGE>

                                                                   EXHIBIT 10.68

                         AGREEMENT FOR THE PURCHASE AND
                       SALE OF EMISSION REDUCTION CREDITS

     THIS AGREEMENT is made as of the 22nd day of August, 2002 by and between
Borden Chemicals and Plastics Operating Limited Partnership, a Delaware limited
partnership ("Seller") and Weyerhaeuser Company, a Washington corporation
("Buyer").

     WHEREAS, Seller is the owner of certain volatile organic compound ("VOC")
Emission Reduction Credits ("ERCs"), which are defined in and governed by the
Louisiana Air Pollution Control Act (33:III, Chapter 6, et seq.), including ERC
banking rules.

     WHEREAS, Seller filed a voluntary petition for relief under chapter 11 of
the Bankruptcy Code, 11 U.S.C. Sections 101-1330 (as now in effect or hereafter
amended, the "Bankruptcy Code"), on April 3, 2001 in the United States
Bankruptcy Court for the District of Delaware (the "Bankruptcy Court").

     WHEREAS, the subject ERCs result from emission reductions of VOC that were
created at Seller's Ascension Parish, Louisiana facility.

     WHEREAS, in order to secure a Non-Attainment New Source Review ("NNSR")
permit for its Holden, Livingston Parish, Louisiana facility under Louisiana
Department of Environmental Quality ("LDEQ") new source review regulations.
Buyer desires to purchase from Seller and Seller desires to sell to Buyer 87.2
tons per year ("tpy") of VOC ERCs as soon as they can reasonably do so and
subject to the approval of the Bankruptcy Court.

1.        PURCHASE AND SALE OF ERCs. Subject to approval of the Bankruptcy
     Court, Seller shall sell to Buyer, and Buyer shall purchase from Seller,
     87.2 tpy of VOC ERCs (the "VOC ERCs"). The purchase price shall be
     calculated on the basis of $5,000 per tpy VOC ERCs transferred to Buyer, or
     a total purchase price of $436,000.00 (the "Purchase Price").

2.        BANKRUPTCY COURT APPROVAL.

     (a)  Approval. Seller and Buyer acknowledge that, under the Bankruptcy
          Laws, this Agreement and the sale of the VOC ERCs are subject to
          Bankruptcy Court approval. Seller and Buyer acknowledge that to obtain
          such approval, Seller must demonstrate that it has taken reasonable
          steps to obtain the highest or best offer possible for the VOC ERCs,
          including, but not limited to, giving notice of the transactions
          contemplated by this Agreement to creditors and other interested
          parties as ordered by the Bankruptcy Court, providing information
          about the VOC ERCs to

<PAGE>

          responsible bidders, entertaining higher and better offers from
          responsible bidders and, if necessary, conducting an auction.

     (b)  Motion for Sale Order. Within three (3) Business Days following
          execution of this Agreement by Seller and Buyer, Seller shall file
          with the Bankruptcy Court a motion, together with appropriate
          supporting papers and notices, in form and substance reasonably
          satisfactory to Buyer and its counsel (the "Sale Motion"), seeking the
          entry of an order (the "Sale Order"), pursuant to Chapter 11 of the
          United States Code Sections 105, 363 and 365, (i) authorizing and
          approving, inter alia, the conveyance of the VOC ERCs on the terms and
          conditions set forth herein, (ii) providing that the stay contained at
          Rule 6004(g) of the Federal Rules of Bankruptcy Procedure shall not
          apply and that the order shall be effective and enforceable
          immediately upon entry, (iii) containing a finding that Buyer has paid
          the highest value reasonably attainable for the VOC ERCs and has acted
          in "good faith" within the meaning of Section 363(m) of the Bankruptcy
          Code and (iv) authorizing the payment of the Earnest Money together
          with all earnings thereon to be made to Seller as part of the Purchase
          Price.

     (c)  Bid Procedures. From the date of this Agreement and through the
          consummation of the transactions contemplated hereby or the
          termination hereof, Buyer and Seller agree that Seller may inform any
          and all interested parties that it intends to submit this Agreement to
          the Bankruptcy Court and that any and all other bids or offers with
          respect to the VOC ERCs must be presented to Seller prior to the
          hearing on the Sale Motion.

     (d)  The obligations of the Seller to complete the sale of the VOC ERCs are
          contingent upon the approval of this sale, if necessary, from the
          Bankruptcy Court.

3.        EARNEST MONEY AND BALANCE OF THE PURCHASE PRICE PAYMENT.

     (a)  Simultaneous with the execution of this Agreement, Buyer shall wire to
          Cantor Fitzgerald Brokerage, L.P. ("CF"), $45,235.00, which shall
          consist of a deposit on the Purchase Price in the amount of $43,600.00
          (the "Earnest Money"), and CF's commission in the amount of $1,635.00,
          corresponding to a 3.75% brokerage commission fee on the Purchase
          Price (the "Commission") (the Earnest Money together with the
          Commission shall hereinafter be referred to as the "Earnest
          Deposit.") The Earnest Money shall be applied to the Purchase Price,
          which shall be calculated in accordance with Section 1 above. The
          Earnest Deposit shall be refundable to Buyer upon termination of this
          Agreement pursuant to Section 13.

     (b)  If fewer than 87.2 tpy of VOC ERCs are determined by LDEQ to be
          transferable to Buyer at the time of transfer request by and between
          Buyer

                                        2

<PAGE>

          and Seller, Seller agrees to deliver and Buyer agrees to accept all
          VOC ERCs determined by LDEQ to be transferable to Buyer; the Purchase
          Price shall be reduced by $5,000 for each tpy below 87.2 tpy that is
          transferred to Buyer (the "Adjusted Purchase Price") and the
          Commission shall be adjusted to reflect a 3.75% of the Adjusted
          Purchase Price.

     (c)  Within three (3) business days from the receipt of the notice from
          LDEQ of the transfer of the VOC ERCs to Buyer, Buyer shall wire to CF
          the Purchase Price, minus the Earnest Deposit (the "Balance") plus
          Buyer's share of the Commission corresponding to 1.875% of the
          Purchase Price. Immediately upon receipt of the Balance, CF shall
          transfer to Seller in cash by wire the Purchase Price minus the
          Commission.

     (d)  Upon Buyer's payment of the Purchase Price, the VOC ERCs shall become
          the sole property of Buyer and Buyer shall have no recourse against
          Seller in the event of change of law governing the creation, transfer,
          or use of VOC ERCs.

4.        TRANSFER OF ERCs. Within five (5) business days from the Bankruptcy
     Court Order and upon CFs receipt of the Earnest Money, Seller and Buyer
     shall submit such paperwork as necessary to direct the LDEQ to immediately
     transfer the VOC ERCs from Seller to Buyer. Seller and Buyer shall use good
     faith efforts and take reasonable actions necessary to promptly transfer
     the VOC ERCs to Buyer. Buyer shall be solely responsible for any fee or tax
     associated with the transfer of the VOC ERCs (the "Transfer Fee").

5.        REPRESENTATIONS. Seller and Buyer represent and warrant that each of
     the respective parties have the full corporate power and authority to
     perform their respective obligations under this Agreement. Seller
     represents and warrants that it owns the VOC ERCs; that no litigation is
     pending or, to the Seller's knowledge, threatened with respect to the VOC
     ERCs; and that the execution and delivery of this Agreement will not result
     in any conflict or violation of the Articles of Incorporation or the Bylaws
     of Seller. Seller does not represent or warrant that the Seller's VOC ERC
     transfer application will be approved by the LDEQ, that the ERCs can be
     used by Buyer, or that the LDEQ will approve their transfer to Seller's
     plan approval. Seller makes no representations or warranty regarding the
     future use or marketability of the VOC ERCs.

6.        BROKER'S FEES. Buyer and Seller shall split equally the Commission.
     Buyer represents and warrants to Seller, and Seller represents and warrants
     to Buyer that, aside from CF, no broker or finder has been engaged by it,
     respectively, in connection with this Agreement. By executing this
     Agreement Buyer and Seller direct CF to take actions specified in Section 3
     of this Agreement.

                                        3

<PAGE>

7.        COUNTERPARTS. This Agreement may be executed in two or more
     counterparts, each of which shall be deemed to be an original and all of
     which constitute the same instrument, and may be executed by facsimile
     copy.

8.        SEVERABILITY. In the event any provision of this Agreement is held
     invalid, the parties shall promptly renegotiate in good faith the terms of
     this Agreement as near as possible to its original intent and effect.

9.        ADDITIONAL DOCUMENTS. At the request of either party, the other party
     shall execute and deliver such additional documents and do such other acts
     and things as may be reasonably necessary to assume and carry out the full
     intent and purpose of this Agreement.

10.       ENTIRETY. This Agreement sets forth the entire agreement of the
     parties with respect to the matters contained herein and supersedes and
     replaces all prior understandings, negotiations, and agreements.

11.       TIME IS OF THE ESSENCE. Time is of the essence in this Agreement.
     Failure of a party to insist upon the strict performance of any provision
     of this Agreement shall not constitute a waiver or estoppel against
     asserting the right to require full and timely performance in the future,
     nor shall a waiver or estoppel in one instance constitute a waiver or
     estoppel with respect to a later breach.

12.       NOTICE. All notices and other communications in connection with this
     Agreement shall be sent to the following addresses:

          For Seller:

          Borden Chemicals and Plastics Operating Limited Partnership
          Highway 73
          Geismar, Louisiana 70734
          Attention: Mr. Marshall Owens
          Telephone No.: (225) 673-0671
          Facsimile No.: (225) 673-0672

          with a copy, which shall not alone constitute notice, to:

          Jones, Day, Reavis & Pogue
          3500 SunTrust Plaza
          303 Peachtree Street, N.E.
          Atlanta, Georgia 30308
          Facsimile: (404) 581-8330
          Attention: Neil P. Olack, Esq.

          For Buyer:
          Weyerhaeuser Company
          17391 Florida Boulevard
          Post Office Box 280

                                        4

<PAGE>

          Holden, Louisiana 70744
          Attention: Mr. Robert E. Lane
                     Manufacturing Lumber Manager
          Telephone No.: (601) 783-4075
          Facsimile No.: (601) 783-2818

          With a copy to:

          Mr. Michael M. Rast
          Area Regulatory Affairs Manager
          29 Tom Rose Road
          Post Office Box 2288
          Columbus, Mississippi 39704
          Telephone No.: (662) 245-5264
          Facsimile No.: (662) 245-5228

          And a copy to:

          Cantor Fitzgerald EBS
          19 Old Kings Highway South
          Darien, Connecticut 06820
          Attention: Andy Kruger
          Telephone No.: (800) 228-2955 (ext. 6)
          Facsimile No.: (203) 662-3643

or such other address or facsimile number as such party may hereafter specify
for such purpose by notice to the other party to this Agreement. Each such
notice, request or other communication shall be effective (i) if given by
facsimile transmission, when such facsimile is transmitted to the facsimile
number specified in this Section 12 and the appropriate confirmation is
received, or (ii) if given by any other means, when delivered at the address
specified in this Section 12.

13.       TERMINATION. This Agreement may be terminated and the transactions
     contemplated hereby may be abandoned:

          (a)     by mutual written consent of Seller and Buyer.

          (b)     by Buyer, at any time following the third (3rd) business day
                  after the execution and delivery of this Agreement if Seller
                  shall not have filed the Sale Motion with the Bankruptcy
                  Court.

          (c)     by Buyer at any time following the tenth (10th) business day
                  after (i) the Bankruptcy Court has entered the Sale Order and
                  (ii) upon the receipt of documentation necessary from Buyer to
                  file such transfer application if Seller does not submit a
                  written request for the transfer of the VOC ERCs to the LDEQ.
                  Buyer agrees that it

                                        5

<PAGE>

                  will furnish Seller with all such necessary documents within
                  five (5) days of execution of this Agreement.

          (d)     by Seller (i) if Seller receives an offer or proposal (an
                  "Acquisition Proposal") from any Person other than Buyer
                  relating to any acquisition of all or any part of the Assets
                  (a "Competing Transaction") and Seller determines, in its
                  reasonable sole discretion, that (A) such Acquisition
                  Proposal, if accepted, is likely to be consummated, and (B)
                  such Acquisition Proposal would, if consummated, result in a
                  transaction that is more favorable to Seller and its creditor
                  constituencies with respect to financial terms than the
                  transactions contemplated by this Agreement, or (ii) for any
                  reason for which termination by Seller is authorized by the
                  Bankruptcy Court.

          (e)     by Buyer, if Seller fails to consummate the transactions
                  contemplated by this Agreement and such failure to consummate
                  the transactions is because (i) Seller accepts an Acquisition
                  Proposal, or (ii) Seller breaches its obligations under this
                  Agreement, provided, that, Buyer is not in material breach of
                  this Agreement.

          (f)     Upon termination of this Agreement pursuant to Section 13
                  hereof, all obligations and liabilities of the parties
                  hereunder shall terminate, except for the provisions of
                  Sections 8 and 14. The aforesaid provisions shall survive such
                  termination for the longest period legally permissible.

          (g)     Terminations made per this Section 13 shall be made by written
                  notice to Seller or Buyer and shall be effective upon Seller's
                  or Buyer's receipt of such notice. Within three (3) business
                  days of Seller's or Buyer's receipt of such notice Seller
                  shall remit to Buyer the Earnest Deposit.

          (h)     In the event of termination of this Agreement pursuant to this
                  Section 13, Buyer shall not be entitled to a reimbursement of
                  the Transfer Fee.

14.       APPLICABLE LAW. THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN
     ACCORDANCE WITH THE LAWS OF THE STATE OF LOUISIANA.

                                        6

<PAGE>

Executed as of the date first above written.

                                   SELLER:

                                   BORDEN CHEMICALS AND
                                   PLASTICS OPERATING LIMITED
                                   PARTNERSHIP
                                   By: BCP MANAGEMENT, INC. AS GENERAL PARTNER

                                   By: /s/ Marshall D. Owens, Jr.
                                       -----------------------------------------

                                   Its: SENIOR VICE PRESIDENT - OPERATIONS
                                        ----------------------------------------
                                        Title

                                   BUYER:

                                   WEYERHAEUSER COMPANY

                                   By: /s/ Robert E. Lane
                                       -----------------------------------------

                                   Its: Mfg. Manager
                                        ----------------------------------------
                                        Title

                                        7