New York's main contract, West Texas Intermediate (WTI) light sweet crude for delivery in August, gained 25 cents to $96.18 per barrel in the afternoon.

Brent North Sea crude for September added 19 cents to $116.24.

"I think today is just pretty much a relief rally on the back of heavily sold oil prices yesterday," said Serene Lim, an oil and gas analyst for ANZ bank in Singapore.

Crude prices slumped on Monday -- with WTI falling 1.35 percent -- as traders fretted over the US impasse and European sovereign debt as officials try to agree a second bailout for Greece

Eurozone leaders were preparing for an emergency summit on Thursday to explore methods of preventing a Greek default, which could have destabilising effects on larger European economies.

And in the US senators were struggling to bridge a deep partisan divide and forge a compromise deal to raise the federal government's debt ceiling by August 2 in order to avert a potentially disastrous default there.

In the absence of significant developments on both sides of the Atlantic, crude traders were "still very much uncertain about the market", ANZ bank's Lim said.

Copyright AFP (Agence France-Presse), 2011