World crude oil prices closed at a record high of above 75 dollars Friday amid worries of supply in Iran and Nigeria.

New York's main contract, light sweet crude for delivery in June, added 1.48 dollars to close at 75.17 dollars a barrel, its highest closing price since 1983.

On London's ICE Futures exchange, the price of Brent North Sea crude for June delivery climbed 1.39 dollars to 74.57 dollars a barrel, its record high since 1988.

Traders are still concerned about the possibilities that Iran's oil exports would halt if the United Nations imposes an international sanction on Teheran for its nuclear activities.

Iran will continue peaceful nuclear research, Iranian envoy to international organizations in Vienna Ali Asghar Soltanieh said Friday.

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

Inventories of U.S. commercial crude oil and refined products declined in the week ended April 14, the Energy Department reported Wednesday.

Data showed that the nation's gasoline stockpiles plunged 5.4 million barrels last week to 202.5 million, or 4.6 percent below year ago levels.

Source: Xinhua