We, MCS Mining Industry Lao Co., Ltd., agree that, notwithstanding LS Horizon Limited’s
representation of MCS Mining Industry Lao Co., Ltd. on the matter regarding the Mekong Project, LS
Horizon Limited and LS Horizon (Lao) Limited may, now or in the future, without seeking or
obtaining our further consent, represent Sibelco Asia Pte. Ltd. and Unichamp Lao Co., Ltd. (and their
subsidiaries) in the same matter or other matters where such persons are adverse to MCS Mining
Industry Lao Co., Ltd.