Global oil prices collapsed yesterday below 50 US dollar for the first time in more than five years. The drop was due to strong dollar, plunging equities, demand worries and plentiful crude supplies. The renewed slump came as the Dow index stood down more than 200 points and European equity markets lost more than two percent on fears of a Greek exit from the eurozone. US benchmark West Texas Intermediate for February delivery tumbled to 49.95 dollar per barrel yesterday, touching the lowest level since May 1, 2009. It later stood at 50.27 dollar, down 2.42 dollar from Friday's closing level. London's Brent North Sea crude for February dropped to a similar nadir at 52.66 dollar a barrel. Oil has dropped about 50 per cent since June on worries about weak demand and a decision by the Organization of the Petroleum Exporting countries not to cut output in response to lower prices.