Prices were also lifted by worries about Tropical Storm Dolly, the first storm of the 2008 Atlantic hurricane season that could disrupt oil production in the Gulf of Mexico.

Last week crude slumped over $16, the biggest decline in dollar terms since futures began trading in New York in 1983 and in percentage terms the steepest sell-off since late 2004.

“The outcome of the Geneva meeting with Iran was quite a disappointment and was the main factor in the lift in oil prices this morning,” said David Moore, a commodities analyst at the Commonwealth Bank of Australia in Sydney.

“The markets had become quite hopeful on Friday that there would be some sort of a resolution, but the meeting over the weekend didn’t result in any guarantees from Iran and that raises the possibility of additional tensions.”

Major powers on Saturday gave Iran two weeks to answer calls to rein in its nuclear program or face tougher sanctions after talks ended in stalemate despite unprecedented US participation.

Prospects of ending the row looked dim as Iran’s top nuclear negotiator Saeed Jalili said Iran would not discuss a demand to freeze sensitive nuclear activities or face tougher sanctions, though Iran’s president on Sunday described the talks as a step forward.

The recent war of words between Iran and the West over Tehran’s nuclear program have heightened tensions in the Middle East and helped push oil prices to a record high of $147.27 earlier this month.

Worries that Tropical storm Dolly could hit the Gulf of Mexico also boosted oil prices on Monday.

The storm headed for Mexico’s Yucatan Peninsula, but the US National Hurricane Center in Miami said it posed no immediate threat to Gulf oil installations slightly south of its projected path.

Foreasters expect Dolly to emerge into the Gulf of Mexico on Monday local time, north of the country’s huge Cantarell oil field and other ports and platforms used by the world’s sixth-largest oil producer and top supplier to the United States.

In Brazil, a national oil workers strike that had a limited impact on Petrobas‘ output ended at midnight on Friday but more walkouts loomed on the horizon.

Despite oil’s rebound on Monday, analysts said worries about the health of the US economy due to the housing crisis would continue to weigh on oil prices, which have shed over $18, or 13%, from the peak struck on July 11. (Reuters)