The selloff in global oil markets showed little signs of slowing in the new year, with prices down as much as 6 percent on Monday, the lowest since spring 2009, as fears deepened a supply glut that has vexed the market for six months would continue. U.S crude crashed below $50 a barrel while benchmark Brent tumbled under $53 after data showed Russian oil output at post-Soviet era highs and Iraqi oil exports near 35-year peaks.