Global oversupply, huge stockpiles and refinery shutdowns have led to plunging prices for US crude oil.<br /><br /> It tumbled by 3 percent on Thursday and by Friday morning hit its lowest in almost six and a half years at 41.35 dollars a barrel. <br /><br /> Brent crude traded at 49 dollars a barrel, down 22 cents but still some way off the 45.19 dollars per barrel it touched at the start of the year.<br /><br /> US crude is much weaker than the North Sea benchmark partly due to a spate of refinery outages that have sapped US demand.<br /><br /> Analysts believe prices could fall further with the latest price drop not enough to put the brakes on the US supply growth.
