Oil prices have slipped slightly after a threat to Nigerian crude flows receded, but lingering concerns of a possible severe disruption to supplies ahead of winter held the market close to $50 a barrel.
US light crude slid 37 cents to $49.75 a barrel, while London's Brent crude fell 43 cents to $46.19 a barrel.
Oil came under some selling pressure after rebels in Nigeria withdrew a threat to shut oil operations in the world's seventh-biggest exporter as part of a peace deal negotiated with the government.
The agreement, struck on Friday, was enough to avert an imminent explosion of violence in the oil-producing Niger delta, a delegate to the talks said, but was a long way from resolving all the misgivings of its impoverished inhabitants.
The threat to Nigerian crude flows of about 2.3 million barrels per day (bpd) came at a time when producers are pumping almost at full tilt, leaving little slack in the system, and drove up US crude prices to a record $50.47 last week.
Nigeria's top oil producer, Royal Dutch/Shell Group, said it was monitoring the security situation in the delta before returning some 300 workers evacuated last month to escape clashes between rebels and troops.
"There is relative calm, but we need to see how sustainable it is before resuming those operations," said a Shell spokesman.
The world's top economic leaders from the Group of Seven countries on Friday urged oil producers to pump more crude to bring down prices, which threaten to stunt economic growth.
