LONDON (AFP) - Oil prices topped 80 dollars a barrel on Monday as a strike at French energy giant Total and concerns over Irans nuclear programme rattled the market, analysts said. New Yorks main futures contract, light sweet crude for delivery in March, hit an intra-day high of 80.51 dollars a barrel. It later stood at 80 dollars, up 19 cents compared with Fridays close. Brent North Sea crude for April delivery gained 25 cents to 78.44 dollars at about 1230 GMT. The sentiment is quite bullish at this time because of the refinery strikes in France and the concerns over Irans 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. Frances govt moved to calm fears of petrol shortages during the open-ended strike at all of oil giant Totals 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 Frances filling stations. Tensions between crude-exporter Iran and the West over Tehrans alleged nuclear weapons ambitions also helped boost prices, analysts said. The US and other world powers are drumming up support for a fourth round of UN sanctions against Iran for its refusal to comply with repeated ultimatums to suspend uranium enrichment and agree to a UN-backed nuclear fuel deal. However, Shum warned that the rally might run out of steam as supply continues to outstrip demand. US crude oil stockpiles rose by nearly 3.1 million barrels to 334.5 million barrels for the week ended February 12, the Department of Energy recently announced. Distillate stocks, including heating oil and diesel fuel, dropped by 2.9m barrels to 153.3m barrels. Northern parts of the US the worlds biggest energy consuming nation experienced extremely cold weather conditions last week which pushed up demand for heating fuel. Oil prices soared last week on a weaker dollar and heightened tensions between crude-exporting Iran and the West, traders said. A weaker US currency makes dollar-priced oil cheaper for buyers using stronger currencies, lifting demand.