LONDON (AFP) - Oil prices sank Friday, mirroring losses on global stock markets, after surging the previous day on news that the United States had emerged from recession. New Yorks main contract, light sweet crude for December delivery, slid 1.76 dollars to 78.11 dollars a barrel. Londons Brent North Sea crude for December dived 1.66 dollars to 76.38 dollars per barrel. Crude prices slid back amid profit-taking, following impressive gains on the back of positive US data, as concerns over poor fundamentals (of supply and demand) continue to linger, said analysts at the Sucden brokerage in London. Wall Street sank Friday as the market digested a sharp rally the day before on news of stronger-than-expected economic growth in the third quarter. Many analysts noted that the GDP expansion was mainly due to exceptional government measures to stimulate growth that would eventually expire. Markets were also rattled on Friday after the US Commerce Department reported that consumer spending dropped 0.5 percent in September. On Thursday, oil rebounded sharply as traders welcomed news that the US returned to economic growth in the third quarter after a year of contraction. The US has now followed France, Germany and Japan in shaking off recession after the worst global economic downturn since the 1930s. The biggest economy in the world grew at a seasonally-adjusted 3.5 percent in the September quarter, beating forecasts for 3.2-percent expansion. The rise was also the biggest since the 2007 third quarter, when the US subprime or higher-risk mortgage market sparked a global financial crisis that dragged the world economy into a steep downturn. Surprisingly good economic figures from the US ... were the catalyst behind the increase in oil prices on Thursday, said JBC Energy analysts. However, they also warned that oil still looks to be overpriced and an increase in GDP after four quarters of decreases does not mean the US, or the rest of the world, is out of the woods yet. The United States is the worlds biggest energy consumer and the health of its economy and the consumption patterns of Americans are major influences. Crude prices have tumbled from record highs above 147 dollars in July 2008 to around 30 dollars in December on falling demand due to the recession. They have since clawed back ground on mounting hopes of global economic recovery. The US third quarter GDP results were very positive and some of the early concerns about the pace of economic recovery therefore eased, said Victor Shum, senior principal at energy consultancy Purvin and Gertz in Singapore. Oil is hanging around 80 dollars and traders are now looking for more economic data to confirm this positive GDP result. Shum said that fragile global demand and oversupply meant that oils inability to sustain prices above 80 dollars was unsurprising. Oil at this pricing level is on shaky ground, he added.