NEW YORK - Oil prices rose on Friday after the International Energy Agency warned of tighter supplies ahead and current unrest in Nigeria, the world's sixth-biggest crude exporter, traders said.
New York's main oil futures contract, light sweet crude for delivery in June, climbed 56 cents to close at 62.37 dollars per barrel.
In London, the price of Brent North Sea crude for June delivery jumped 1.04 dollars to end the day at 66.83 dollars.
On a weekly basis, the price oil rose 0.71 percent in New York and 2.3 percent in London from the previous Friday.
Concerns about tight gasoline stocks in the United States just weeks before the beginning of the summer vacation peak driving season were underscored in the latest monthly report by the International Energy Agency.
The agency reduced its forecast figure for global demand for oil in 2007 by 0.1 million barrels per day from its estimate in April, to 85.7 million barrels because of mild weather in the northern hemisphere and a slightly lower forecast for demand in China.
But it warned: "With average (petrol) retail prices in the US near record highs at just over three dollars per gallon several weeks ahead of the start to the summer driving season, concerns over supplies are being raised."
Eric Wittenauer, an analyst at AG Edwards, said the report "suggests the tight gasoline market will continue to give underlying support to the crude market in the weeks to come."
Earlier in the week, crude futures had fallen after the US Department of Energy (DoE) reported a surprisingly strong build-up in crude stocks of 5.6 million barrels.
The DoE report on Wednesday also showed a gain of 400,000 barrels in gasoline reserves -- the first rise since early February despite market concerns over tight supplies.
But analysts expected the weekly gasoline gain was merely a blip as shutdowns and outages continued to restrict refinery capacity.
"Supply concerns and unfettered energy demand strongly support the bullish case," said John Kilduff of Man Financial.
"This week's inventory report was not enough to assuage the market's concerns over summer gasoline supplies, and we cannot argue that conclusion."
In its report Friday, the Paris-based IEA focused on political unrest in Nigeria, falls in global energy stockpiles and strains in the refining sector.
The influential energy watchdog stressed that "underlying worries about product availability in the summer are concerns that geopolitics could threaten crude supplies, mostly in Nigeria."
Oil prices rallied Thursday on concerns about unrest in Nigeria, the biggest oil producer in Africa, where an estimated quarter of the output has been slashed due to a series of attacks on energy facilities in the crude-rich Niger delta.
On Thursday, gunmen killed two policemen on the outskirts of Port Harcourt, Nigeria's oil capital, police there said, less than two days after three naval personnel were wounded when the construction vessel they were guarding offshore was attacked.
Four US oil workers had been seized by gunmen in southern Nigeria, officials said Wednesday, adding to a list of dozens of foreigners taken hostage in recent weeks.
05/11/2007 20:12 GMT