Mauritania's government vowed to use all possible legal actions to try to annul disputed amendments to oil production sharing contracts signed with Australia's Woodside Petroleum Ltd. The dispute threatens to overshadow the scheduled production start-up this month of a major offshore oil project operated by Woodside, which will turn the poor, largely desert-covered West African state into the continent's newest oil producer. Mauritania, whose new military rulers took power in a bloodless coup in August 2005, says it cannot accept the Woodside contract amendments, which were signed more than a year ago by a former oil minister who is now in prison facing trial for corruption.