Benchmark crude for April delivery was up 34 cents at $97.31 a barrel at midday Singapore time in electronic trading on the New York Mercantile Exchange. The contract lost 91 cents to settle at $96.97 on Monday.

In London, Brent crude for April delivery was up 65 cents to $112.45 a barrel on the ICE Futures exchange.

Libya's top oil official, Shukri Ghanem, said Monday that the country's crude production had been cut by around 50 percent, or about 800,000 barrels a day. International pressure increased on Libyan leader Moammar Gadhafi to step down as his supporters and opponents fought in towns outside the capital, Tripoli.

So far Libya has been the biggest oil producer to see exports disrupted by political uprisings this year that have toppled governments in Tunisia and Egypt and sparked violent protests in Yemen, Iran, Oman, Bahrain, Algeria and Morocco.

Oil traders are most concerned the unrest could spread to Saudi Arabia, the world's largest crude exporter. Some analysts expect oil prices will drop once Gadhafi resigns or Libyan oil exports stabilize.

"Sharply higher energy prices are a clear threat to the world economy and to emerging markets," Citigroup said in a report. "However, most likely, this phase will pass, oil prices will be contained and markets will rally."

In other Nymex trading in April contracts, heating oil rose 0.6 cent to $2.94 a gallon and gasoline gained 0.6 cents to $2.90 a gallon. Natural gas futures were down 0.6 cent at $4.03 per 1,000 cubic feet.