By early afternoon in Europe, benchmark crude for April delivery was up 33 cents to $98.21 a barrel in electronic trading on the New York Mercantile Exchange.
The contract rose 60 cents to settle at $97.88 on Friday. In London, Brent crude for April delivery was up 46 cents to $112.60 a barrel on the ICE Futures exchange.
In volatile trading, both contracts were well off their peaks from earlier in the session: Nymex reached $99.96, while Brent briefly touched $114.50.
As fighting between supporters and opponents of Libyan leader Moammar Gadhafi continued over the weekend, foreign oil companies scrambled to evacuate staff.
The chaos in Libya's oil industry has cut production by at least 750,000 barrels daily, down from its normal capacity of 1.6 million barrels, the International Energy Agency reported late Friday.