Promissory Note Between Gastar Exploration LTD. And Geostar

Exhibit 10.9


PROMISSORY NOTE

U.S.$15,000,000 Houston, Texas August 11, 2005


FOR VALUE RECEIVED, the undersigned, Gastar Exploration, Ltd., an Alberta, Canada corporation whose office is located at 1331 Lamar, Suite 1080, Houston, Texas 77010 (" Obligor" ), promises to pay to the order of GeoStar Corporation, a Delaware corporation, or its registered assigns (" Payee" ) at 2480 West Campus Drive, Building C, Mt Pleasant, MI 48858 or at such other place as Payee may designate in writing, in lawful money of the United States of America, the principal amount of FIFTEEN MILLION DOLLARS ($15,000,000), together with interest thereon, computed on the basis of a 365-day year for the actual number of days elapsed, at the rate of 4.5% above the 3-Month London Interbank Offered Rate (LIBOR) per annum, with the 3-Month LIBOR rate determined as of the start of each calendar quarter. Interest shall accrue as of the date hereof.

Obligor shall pay to Payee installments of One Million Five Hundred Thousand U.S. Dollars (US $1,500,000) each beginning February 15, 2006, and on the 15th day of each of the next nine (9) succeeding months.


Obligor shall pay, on February 15, 2006, all interest accrued and unpaid up to but excluding such date. All remaining accrued interest shall be paid on March 15, 2006, and on the 15th day of each succeeding month until the principal balance shall be paid in full. Obligor shall have the option to pay all interest related to this Note in-kind in the form of additional notes that will be due January 15, 2007.

Obligor may prepay this Note in whole or in part at any time without penalty or premium. Any such prepayment shall be applied first against accrued interest and then against principal. This Note is given under a certain Agreement (" Agreement" ) of even date herewith by and among Payee and Obligor, together with certain subsidiaries of Obligor. Reference is hereby made to that Agreement f ...