A deadline is due to expire on Sunday in Nigeria for armed groups fighting in the Niger delta to accept a government amnesty and disarm.
In return the government has offered to pay and train them.
Government Tompolo, who heads the main rebel faction in the western Delta, gave up his weapons on Saturday, 24 hours before the offer expired.
Two other commanders from the eastern Delta also laid down their weapons on Saturday.
The BBC reports the amnesty offer by President Umaru Yar'Adua is part of government efforts to end years of rebel attacks on the Nigerian oil industry.
Rebels in the Delta have claimed responsibility for numerous attacks on Nigeria's oil infrastructure, as well as kidnappings for ransom.