New York's main futures contract, light sweet crude for delivery in March, hit an intra-day high of $80.51 a barrel. It later stood at $80.02, up 21 cents compared with Friday's close.

Brent North Sea crude for April delivery gained 22 cents to $78.41 per barrel.

"The sentiment is quite bullish at this time because of the refinery strikes in France and the concerns over Iran's nuclear issues," said Victor Shum, an analyst at Purvin and Gertz energy consultants.

A strike by workers of energy major Total entered its sixth day on Monday.

France's government moved to calm fears of petrol shortages during the open-ended strike at all of oil giant Total's refineries, as families hit the road for the half-term school holiday.

Some French drivers rushed to fill their tanks on Sunday after workers at Total raised the threat of shortages. AFP reporters in towns such as Rennes and Toulouse saw queues at filling stations and some pumps ran dry.

Total supplies about half of France's filling stations.

Meanwhile, US stocks eased and the US dollar rose against the euro on Monday as investors worried about the sustainability of the economic recovery in the wake of last week's discount rate rise by the Federal Reserve.

Concern about Greece's indebtedness continued to weigh on the euro and supported the dollar.

The stronger dollar helped drive down gold after it hit a one-month high earlier and as risk appetite eased, which also sent oil down from six-week highs.

The Dow Jones Industrial Average was down 7.86 points, or 0.08 percent, at 10,394.49. The Standard & Poor's 500 Index was down 1.23 points, or 0.11 percent, at 1,107.94. The Nasdaq Composite Index was down 3.70 points, or 0.16 percent, at 2,240.17.

European equities ended lower after advancing in the previous five sessions as weaker drug makers and food producers pressure the market, but analysts said overall momentum remained positive.

The FTSEurofirst 300 index of top European shares provisionally closed 0.28 percent lower at 1,02315 points.

The European index is down 2.0 percent in 2010, partly on worries that China's moves to slow its economy and a potential Greek debt default may slow world economic growth.

Gold fell as well as risk appetite eased and the dollar firmed. Strength in the US currency tends to pressure dollar-denominated commodities.

The US dollar, against major currencies as measured by the ICE Futures Exchange's dollar index, was down 0.07 percent at 80.585.

The euro was down 0.18 percent at $1.3592 as lingering worries about Greece's public finances capped its gains, while the dollar was down 0.45 percent against the yet at 91.17.