Exhibit 10.1

LIMITED WAIVER TO

CONSTRUCTION LOAN AGREEMENT

This LIMITED WAIVER TO CONSTRUCTION LOAN AGREEMENT (this “ Limited Waiver ”), dated as of August 17, 2009, is entered into by and among the following parties:

(a) TIETEK LLC, a Delaware limited liability company (the “ Borrower ”);

(b) NORTH AMERICAN TECHNOLOGIES GROUP, INC., a Delaware corporation (the “ Company ”), and TIETEK TECHNOLOGIES, INC., a Texas corporation (“ TTT ”) (the Company and TTT shall be collectively referred to as the “ Borrower Affiliates ” and the Borrower Affiliates and the Borrower shall be collectively referred to as the “ Borrower Group ”); and

(c) OPUS 5949 LLC, a Texas limited liability company (the “ Lender ” and, together with the Borrower Group, the “ Parties ”).

RECITALS

A. The Borrower, the Borrower Affiliates, and the Lender entered into that certain Construction Loan Agreement, dated as of February 5, 2004, as amended by (1) that certain Release, dated February 22, 2005, (2) that certain Limited Waiver and First Amendment to Construction Loan Agreement, dated July 7, 2005, (3) that certain Second Amendment to Construction Loan Agreement, dated December 29, 2005, (4) that certain Third Amendment to Construction Loan Agreement, dated September 18, 2006, and (5) that certain Fourth Amendment to Construction Loan Agreement, dated July 24, 2007 (as so amended and as further amended, restated, supplemented or otherwise modified from time to time, the “ Loan Agreement ”), pursuant to which the Lender agreed to make available to the Borrower Group certain financial accommodations and modifications to the Loan Documents.

B. The Borrower and the Borrower Affiliates have requested that, subject to the terms, conditions, covenants and limitations contained in this Limited Waiver, the Lender agree that the interest payment otherwise due and payable by Borrower under the Loan Agreement and the other Loan Documents on July 1, 2009 and waived until July 31, 2009 pursuant to the Limited Waiver to Construction Loan Agreement dated July 1, 2009, would be further waived until August 17, 2009, and that any Default or Event of Default that has occurred or may occur, solely by reason of the failure of Borrower to make such interest payment when otherwise due and payable under the Loan Agreement (the “Specified Interest Payment Default”), shall be waived until 5:00 p.m. (Dallas time) on August 31, 2009;

C. The Lender has agreed to the actions described in Paragraph B preceding, in each instance upon and subject to the terms, conditions, covenants and limitations contained in this Limited Waiver.

ACKNOWLEDGMENTS:

(a) The Borrower and the Borrower Affiliates hereby acknowledge and agree to the accuracy of all Recitals included in this Limited Waiver.

(b) The Borrower and the Borrower Affiliates acknowledge and agree that all amounts advanced to, or for the benefit of, the Borrower, including, but not limited to, the Loan prior to the date hereof are, and shall continue to be, obligations under the Loan Documents (the “ Obligations ”) and subject to all the terms and conditions in the Loan Agreement and the other Loan Documents.

(c) The Borrower and the Borrower Affiliates acknowledge and agree that (i) as of July 31, 2009, the outstanding principal and accrued but unpaid amount of the Obligations is $14,353,888.89, of which $14,000,000.00 is the amount of outstanding principal of the Note and $53,888.89 is the amount of accrued but unpaid interest thereon; and (ii) the Obligations are enforceable against the Borrower without offset, reduction, or counterclaim.

AGREEMENTS

NOW, THEREFORE, in consideration of the premises herein contained and other good and valuable consideration, the sufficiency of which is hereby acknowledged, the Parties hereto, intending to be legally bound, agree to the above Recitals, Acknowledgments and as follows:

1. DEFINITIONS . All capitalized terms used but not otherwise defined in this Limited Waiver shall have the meanings ascribed to them in the Loan Agreement.

2. LIMITED WAIVER . Subject to the terms and conditions set forth in this Limited Waiver and the Borrower’s and the Borrower Affiliates’ acknowledgments and agreements set forth above, and expressly conditioned upon the absence of any Event of Default other than the Specified Interest Payment Default, the Lender hereby (a) agrees that the interest payment otherwise due and payable by Borrower under the Loan Agreement and the other Loan Documents on July 1, 2009, and previously waived until July 31, 2009, and August 17, 2009 shall be waived until August 31, 2009 and (b) waives the Specified Interest Payment Default until 5:00 p.m. (Dallas time) on August 31, 2009. The waiver agreed to herein (i) is temporary only and, if the interest payment waived by this Limited Waiver has not otherwise been made to and received by the Lender at or prior to 5:00 p.m. (Dallas time) on August 31, 2009, the waiver shall terminate and, as a result, the waiver shall no longer be valid and shall not impair, restrict or limit any right or remedy of the Lender with respect to the Specified Interest Payment Default under the Loan Agreement or any of the other Loan Documents, (ii) is strictly limited to the Specified Interest Payment Default, shall not be deemed to be a consent to any amendment, waiver or modification of any term or condition of the Loan Agreement and the other Loan Documents, and except as expressly set forth in this Limited Waiver, all the other terms, provisions and conditions of the Loan Agreement and the other Loan Documents shall remain in full force and effect, (iii) shall not extend nor be deemed to extend to any other Default or Event of Default that may now exist or hereafter arise under the Loan Agreement or any of the other Loan Documents, (iv) shall not impair, restrict or limit any right or remedy of the Lender with respect to any other Default or Event of Default that may now exist or hereafter arise under the Loan Agreement or any of the other Loan Documents, and (v) shall not constitute any course of dealing or other basis for altering any obligation of any member of the Borrower Group or any right, privilege or remedy of the Lender under the Loan Agreement or any of the other Loan Documents. No failure on the part of any Lender to provide a notice hereunder or otherwise exercise, and no delay in providing any notice or otherwise exercising, any right, power, remedy or privilege under this Limited Waiver, shall operate as a waiver thereof, nor shall any single or partial exercise of any right, power, remedy or privilege under this Limited Waiver preclude any other or further exercise thereof or the exercise of any other right, power, remedy or privilege.

3. REFERENCES TO LOAN AGREEMENT, ETC. All references to the “Loan Agreement” or the “Construction Agreement” or other similar terms intended to refer to the Loan Agreement in each of the Loan Documents and in any other documents or agreements by, between or among any of the Borrower Group an