World crude oil prices shed slightly Monday amid worries of supply in Nigeria and Iran, but still hovered above 64 dollars a barrel.

New York's main contract, light sweet crude for delivery in May, lost 10 cents to end at 64.16 dollars a barrel.

On London's ICE Futures exchange, the price of Brent North Sea crude for May delivery dipped 7 cents to end at 63.44 dollars a barrel.

On the New York Mercantile Exchange, the heating oil rose 1.13 cents to close at 1.7811 dollars a gallon as gasoline futures fell 0.56 cents to settle at 1.8288

dollars per gallon. Natural gas futures dipped 22.3 cents to finish at 7.067 dollars per 1,000 cubic feet.

Three Western oil workers, two Americans and a Briton, held in Nigeria's troubled oil-rich Niger Delta by militants for more than one month, had been released, a state government spokesman said on Monday. However, Royal Dutch Shell said that it will not be eager to restore oil production in Nigeria.

Nigeria is Africa's leading oil producer and the fifth-biggest source of U.S. oil imports. About one-fourth of the country's daily output is still shut after a series of militant attacks.

Traders are still concerned about the possibilities that Iran's oil exports would halt if the United Nations imposes Teheran an international sanction for its nuclear activities. Iran is OPEC's number-two producer behind Saudi Arabia, producing four million bpd of oil and exporting 2.4 million bpd.

The Department of Energy said Wednesday that U.S. commercial crude oil inventories fell unexpectedly in the week ended March 17 while supplies of gasoline and other refined products also declined. It was the first weekly drop in commercial crude oil reserves since early February.

Source: Xinhua