The military leaders who ousted Niger's government last month are reviewing the lucrative uranium mining contracts held there by French nuclear group Areva, the company said on Friday.

Niger has told Areva it is scrutinizing the deals and the company is "making available to the Niger authorities all the details of the commercial contracts it has made with the country," a company spokeswoman told AFP.

Half of Areva's uranium comes from Niger, a former French colony in west Africa where the company has been mining at two sites since the late 1960s. The country ranks among Africa's poorest despite its rich deposits of uranium.

Areva has also signed a deal to start tapping a third mine in Niger from 2013 or 2014.

A military junta has been in power in Niger since mid-February when it overthrew the government of president Mamadou Tandja, who changed the constitution in a disputed referendum to cling to power.

It has appointed a 20-member cabinet, including five senior army officers, to run Niger for a transitional period, aiming to pave the way for a return to democracy.