LONDON (AFP) - Oil prices slumped on Tuesday as investors locked in profits from recent sharp gains. New Yorks main futures contract, light sweet crude for delivery in April, slid 1.43 dollars to 78.88 dollars a barrel. The March contract had closed at 80.16 dollars as it expired Monday after rising for five consecutive sessions on growing signs of a firmer global economic recovery. Supply worries owing to a strike at French energy major Total and tensions between crude-exporter Iran and the West over Tehrans nuclear weapons ambitions had also helped bolster prices, analysts said. Those factors, however, can only temporarily support the oil price, as long as the underlying fundamental (supply and demand) data remain weak, said Commerzbank analyst Carsten Fritsch. During the past several months, price movements beyond 80 dollars were only short-lived. Hence, this time, a break through this level is in our view also rather unlikely, as last weeks fundamental situation on the oil market did not significantly improve. On Tuesday at about 1230 GMT, Londons Brent North Sea crude for April shed 1.41 dollars to 77.20 dollars a barrel. One analyst said it would be difficult to support oil at more than 80 dollars because supply still outstripped demand. On the demand side sentiment has been quite positive... but I think 80 dollars is pretty high given where the fundamentals are, said National Australia Bank analyst Ben Westmore. It could move a bit further upwards, but I wouldnt expect it to continue a sustainable upward trend from here, especially while stocks of production in the US are still pretty high. The Centre for Global Energy Studies said in its latest monthly report that global oil demand was growing again following the economic downturn, driven by China. Global oil demand is growing again, driven by surging apparent demand in China and boosted by a protracted and widespread spell of cold weather across much of the Northern Hemisphere, the research group said in a report published on Monday. The outlook remains far from certain, though, it added. Meanwhile on Tuesday, French President Nicolas Sarkozy stepped into an industrial row that has caused hundreds of fuel pumps to run dry in France, ordering oil giant Total to guarantee it will not shut refineries. The government wants Total to make commitments not to close its refining operations in the coming years, government spokesman Luc Chatel told reporters after Sarkozy met the French groups chief executive Christophe de Margerie. Thats what the president demanded and thats what they talked about, he said, after Sarkozy briefed ministers on his meeting. Drivers have been rushing to fill up their tanks this week to avoid running out during the mid-term school holiday. Total said on Tuesday that 249 of its 2,600 Elf service stations in France had run out of at least one fuel product. It has agreed to meet unions Tuesday.