Global crude oil prices fell sharply, today, after official data showed that China's giant manufacturing sector, one of the main engines powering the world's biggest energy consumer, contracted at its fastest pace in three years. The figures helped spur a retreat in oil prices after three days of hefty gains. Brent crude oil futures dropped 2.45 dollars, to 51.70 dollars a barrel. U.S. crude was down 75 cents, at 48.45 dollars a barrel. Oil prices have rallied from their lowest levels since the global financial crisis after figures from the Energy Information Administration pointed to lower-than-expected U.S. oil production. But despite the lower U.S. production, the global market is still heavily oversupplied. Bank of America Merrill Lynch has lowered its 2016 and 2017 crude oil projections because balances looked soft and oil production costs were falling.