U.S. crude oil prices fell to almost $40 a barrel on Thursday, its lowest since the global financial crisis of 2009, as supplies rose in North America and the Middle East, filling stockpiles to record levels. Oil has lost a third of its value since June on high U.S. production, record crude pumping in the Middle East and concern about falling demand in Asian economies. All the main oil futures contracts looked to be heading lower, PVM Oil Associates director and technical analyst Robin Bieber said.