| **Re:** | **Amendment                  No. 4 (“Amendment No. 4) to the Exclusive License Agreement, dated March                  20, 2006 and as amended September 11, 2006, December 13, 2006 and                  November                  3, 2007 between Ferdinando Petrucci (“Petrucci”) and H2Diesel, Inc.                  (“H2”)  (as amended, the “License                  Agreement”)** |
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| 1.   | The                due date for the US$1,500,000 payment required under section 1(b)(i)(C)                of                the License Agreement is extended from November 15 2007 to November                29, 2007. |
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| 2.   | H2Diesel                will pay Petrucci US$2,000,000 on or before November 29, 2007, with                US$1,500,000 of such payment allocated to the payment formerly due                on                November 15, 2007 and US$500,000 of such payment allocated as a prepayment                of the US$1,000,000 payment due on March 20, 2008 under section 1(b)(i)(D)                of the License Agreement. |
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| 3.   | H2Diesel                will pay Petrucci the remaining US$500,000 of the payment due in                2008                under section 1(b)(i)(D) of the License Agreement on February 20,                2008. |
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| 4.   | H2Diesel                will pay Petrucci the US$1,000,000 payment formerly due on March                20, 2009                under section 1(b)(i)(D) of the License Agreement on February 20,                2009. |
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| 5.   | H2Diesel                will pay Petrucci US$500,000 of the US$1,000,000 payment due in 2010                under section 1(b)(i)(D) of the License Agreement on February 20,                2010. |
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|                                                                                                                                       |                                  |
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| By:                                                                                                                              | /s/                David A. Gillespie |
| Name:                  David A. Gillespie     Title:                  President and Chief Executive Officer  |

|  /s/                  Ferdinando Petrucci   |
|------------------------------------------------------------|
| Ferdinando                    Petrucci                     |

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