A TRUCE called by Nigeria's leading militant group may provide a brief respite in a conflict crippling Africa's biggest oil producer but is unlikely to end the fight unless the government addresses decades-old grievances such as pollution, underdevelopment, corruption and lack of freedom. The Movement for the Emancipation of the Niger Delta has been attacking oil installations, kidnapping petroleum company employees and fighting government troops since January 2006 in what it calls a protest against the unrelenting poverty of people in the Niger Delta. Nigeria's military has fighting a losing battle against opponents using guerrilla tactics in an intricate network of lagoons, creeks, estuaries and mangrove swamps stretching across 640 million acres – home to several minority groups and some of Africa's largest oil deposits. The poverty there has been deepened by more than 50 years of oil production: soil once used for crops is sticky from crude oil leaks, rivers that used to provide fish are slick with oil and the air is acrid with fumes from decades of gas flaring. The Movement for the Emancipation of the Niger Delta called the cease-fire Wednesday saying the government had met one of its demands by releasing ailing rebel leader Henry Okah. It said it wants to negotiate with the government, is busy identifying envoys and hopes the 60-day cease-fire will create “an enabling environment” for negotiations. President Umar Yar'Adua's special adviser on the southern Delta region, where all Nigeria's oil is produced, responded that the president was “sincere and committed, and is truly poised to turn the Niger Delta into a bastion of peace and development.” But the rebel group has called cease-fires before, the government has made similar promises and all has come to naught. In January, the group called off a four-month cease-fire alleging that the government had broken it, though the government denied that. The most pressing issue, one the government can address most speedily, is the 13 percent share of national oil revenue allocated to the delta under Nigeria's federal system. Various groups in the region have been demanding an increase that would bring that share up to anywhere from 25 percent to 100 percent of revenue. But Yar'Adua's government, like its predecessor, is showing little enthusiasm and faces political resistance from other parts of the country that automatically must accept less revenue if more goes to the delta. The economy of Nigeria, Africa's most populous nation of 140 million, is almost totally dependent on oil. “The fear is that unless the government seizes this opportunity to show good faith and sincerity and commitment to addressing the substantive issues in the Niger Delta, then this might just be an interlude before we get to another phase of violence,” said Nnamdi Obasi, a Lagos-based analyst for the International Crisis Group. Economist Peter Alexander Egom was pessimistic, saying Wednesday's moves are “really cosmetic because both sides are not ready to give up their stand; The Nigerian government wants control of that area and cannot do so unless MEND is defeated.” Pressure on the government could come from Western oil companies that are taking huge losses because of the insurgency. Nigeria was producing about 2.4 million barrels of crude a day before MEND launched its most successful attacks. Production is down to about 1.7 million barrels a day. Yar'Adua took a conciliatory approach when he became president in 2007 but, since he did nothing about the root grievances, nothing was resolved and he was persuaded to try force. The military launched its most punishing offensive in years in May. As usual, innocent civilians suffered most with thousands driven from their homes by soldiers while the militants continued to attack oil stations and pipelines. Those recent attacks alone forced Royal Dutch Shell, Chevron and Agip to stop pumping more than 300,000 barrels a day. None of the oil companies would comment on the cease-fire, saying they do not get involved in politics. On June 25, Yar'Adua offered amnesty to all militants who surrender their weapons and renounce armed struggle within 60 days. Militants rejected that offer. On Sunday, they struck outside the delta for the first time, setting ablaze an oil depot and loading tankers in Lagos, the most populous city. Hours later, the government met one of the rebel demands and released Okah, the ailing militant leader. And Yar'Adua appointed a new defense minister, Godwin Abbe, who has held many positions in the delta and heads the presidential committee on the amnesty.