Two key militant leaders in Nigeria's oil-producing Niger Delta have started informal talks with the government about surrendering their weapons in return for clemency, an amnesty committee spokeswoman said on Tuesday.

Representatives of Ateke Tom and Government Tompolo, the leaders of factions of the Movement for the Emancipation of the Niger Delta (MEND), have spoken with government officials about accepting an amnesty offer, said Timiebi Koripamo-Agary, spokeswoman for the presidential panel on amnesty.

"We are discussing with them, but it is all informal," she told Reuters. "We are assuring them that the amnesty is for real as they have expressed concern about their personal security."

President Umaru Yar'Adua in June offered amnesty to gunmen in the Niger Delta to try to stem unrest which has prevented Nigeria from pumping much above two-thirds of its oil capacity, costing it billions of dollars a year in lost revenues.

The amnesty programme has split militant factions in the region, with hundreds of rebels, including some senior leaders, handing over weapons but others refusing to take part.

MEND, which has warned it will resume attacks once a ceasefire period ends in two weeks, said it was abandoning militant leaders who engaged in talks with the government.

"MEND is shedding most of its popular commanders whose identities have become known to government agents as this will not make our secrecy style effective," the group said in an email to Reuters.

"It is possible (Agary) may have had private talks with Ateke and Tompolo but this has nothing to do with MEND ... MEND has not returned to the negotiating table and talks remain suspended until we announce a resumption," the email said.

(REUTERS)