World crude oil prices retreated Thursday as traders took profit,after hitting record highs amid worries of supply in Iran and Nigeria.

New York's main contract, light sweet crude for delivery in May, was down 22 cents to close at 71.95 dollars a barrel, after touching intra-day high of 72.49 dollars, its record high since 1983.

On London's ICE Futures exchange, the price of Brent North Sea crude for June delivery lost 55 cents to close at 73.18 dollars a barrel, after touching intra-day high of 74.22 dollars, its record high since 1988.

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.

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.

Source: Xinhua