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                                                                    EXHIBIT 4.12

                           NORD RESOURCES CORPORATION

                             3048 N. Seven Dash Road
                                  P.O. Box 384
                             Dragoon, Arizona 85609

                                                   Dated as of: November 8, 2004

Regiment Capital III, L.P.
222 Berkely Street, 12th Floor
Boston, Massachusetts 02116

Re: Amendment No. 1 to Post Closing Letter

Ladies and Gentlemen:

     We refer to that certain post-closing letter, dated October 19, 2004 (the
"Post-Closing Letter"), by Nord Resources Corporation, a Delaware corporation
(the "Borrower") and Regiment Capital III, L.P., a Delaware limited partnership
(the "Lender") delivered in connection with that certain Promissory Note, dated
October 19, 2004 (as amended, the "Note").

     Terms used in this Amendment No. 1 to the Post-Closing Letter (this
"Amendment") which are not defined herein, but which are defined in the Note,
shall have the same respective meanings herein as therein.

     We have requested you to make certain amendments to the Post-Closing
Letter. You have advised us that you are prepared and would be pleased to make
the amendments so requested by us on the condition that we join with you in this
Amendment.

     Accordingly, in consideration of these premises, the promises, mutual
covenants and agreements contained in this Amendment, and for other good and
valuable consideration, the receipt and sufficiency of all of which are hereby
acknowledged, the parties hereto, fully intending to be legally bound by this
Amendment, agree as follows:

     1. Effective as of November 18, 2004 (the "First Amendment Date"), the
     Post-Closing Letter is amended as follows:

          (a)  Paragraph 3 is hereby deleted and replaced in its entirety as
               follows:

               "Within ninety (90) days of the date hereof, the Borrower shall
               deliver to the Lender a deposit account control agreement for the
               Borrower's securities account held with A.G. Edwards; provided,
               however, that if as of such date there are no securities held in
               such account, and no purchases

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               of securities have been made from or through such account within
               sixty (60) days prior to such date, then the A.G. Edwards account
               may be closed and no Blocked Account Agreement shall be required
               with respect thereto."

     2. This Amendment has been duly executed and delivered to the Lender by the
     Borrower and is in full force and effect as of the date hereof, and the
     agreements and obligations of the Borrower contained herein constitute
     legal, valid and binding obligations of the Borrower enforceable against
     the Borrower in accordance with their respective terms.

     3. This Amendment may be executed in any number of counterparts, each of
     which when executed and delivered shall be deemed an original, but all of
     which together shall constitute one instrument. In making proof of this
     Amendment, it shall not be necessary to produce or account for more than
     one counterpart thereof signed by each of the parties hereto. Except to the
     extent specifically amended and supplemented hereby, all of the terms,
     conditions and the provisions of the Post-Closing Letter shall remain
     unmodified.

     If you are in agreement with the foregoing, please sign the form of
acceptance on the enclosed counterpart of the Amendment and return such
counterpart to the undersigned, whereupon this Amendment, as so accepted by you,
shall become a binding agreement between you and the undersigned.

                                         Very truly yours,

                                         NORD RESOURCES CORPORATION


                                         By: /s/ Erland Anderson
                                             -----------------------------------
                                         Name: Erland Anderson
                                               President

The foregoing Amendment is hereby accepted by the undersigned as of November 8,
2004.

REGIMENT CAPITAL III, L.P.

By: REGIMENT CAPITAL MANAGEMENT, LLC, as its General Partner

By: REGIMENT CAPITAL ADVISORS, LLC, as its Manager


By: /s/ Mark Brostowski
    ----------------------------------
Name: Mark Brostowski
      Vice President