World crude oil prices rose above 74 dollars Tuesday amid concerns over Iran.

New York's main contract, light sweet crude for delivery in August, rose 55 cents to close at 74.16 dollars per barrel.

In London, Brent North Sea crude for August delivery advanced 78 cents to close at 73.67 dollars per barrel in electronic trading.

Iranian President Mahmoud Ahmadinejad said on Tuesday that his country would not back down its right to continue nuclear fuel cycle work.

Ahmadinejad said that Iran was determined to obtain all of its rights, including full nuclear rights and complete exploitation of nuclear fuel cycle.

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, making 4 million bpd of oil and exporting 2.4 million bpd.

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