World crude oil prices rose the second day Thursday amid concern over Iran, as U.S. gasoline reserves rose less than expected.

New York's main contract, light sweet crude for delivery in August, gained 51 cents to close at 70.84 dollars per barrel.

In London, Brent North Sea crude for August delivery rose 78 cents to 69.95 dollars per barrel.

UN Secretary-General Kofi Annan said Thursday that Iran is seriously considering the offer of negotiations on its nuclear energy plans made by the five permanent members of the UN Security Council and Germany.

Iranian President Mahmoud Ahmadinejad said Wednesday that Iran will respond by mid-August to the proposals presented to Tehran in early June by EU foreign policy chief Javier Solan.

The U.S. Department of Energy reported Wednesday that gasoline reserves went up 300,000 barrels to 213.4 million last week. The increase was below the advance of 1.5 million barrels that analysts had predicted.

U.S. commercial crude oil inventories rose by 1.4 million barrels to 347.1 million, their highest level since late May 1998, in the week ending June 16.

Supplies of gasoline are closely watched because of the peak demand season in the United States. Over the past four weeks, the nation's demand for gasoline has been running 0.9 percent higher than a year ago.

Source: Xinhua