EXHIBIT (99.1)

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) promulgated under the Securities Exchange Act of 1934, the undersigned agree to the joint filing of a Statement on Schedule 13G (including any and all amendments thereto) with respect to the Common Stock, $0.01 par value, of Magellan Petroleum Corporation and further agree to the filing of this agreement as an Exhibit thereto. In addition, each party to this Agreement expressly authorizes each other party to this Agreement to file on its behalf any and all amendments to such Statement on Schedule 13G.

Date: December 13, 2006

 

ORIGIN ENERGY LIMITED
By:  

/s/ WILLIAM M HUNDY

Name:   William M Hundy
Title:   Secretary
ORIGIN ENERGY RESOURCES LTD
By:  

/s/ WILLIAM M HUNDY

Name:   William M Hundy
Title:   Secretary
SAGASCO NT PTY LTD
By:  

/s/ WILLIAM M HUNDY

Name:   William M Hundy
Title:   Secretary
SAGASCO AMADEUS PTY LIMITED
By:  

/s/ WILLIAM M HUNDY

Name:   William M Hundy
Title:   Secretary