Crude oil prices tumbled on Monday, with Brent and U.S. crude hitting their lowest levels since May 2009, reversing early gains on selling by investors convinced that supply disruptions in Libya would not offset a global supply glut.



U.S. crude settled down $1.12, or 2.1 percent, at $53.61 per barrel, its lowest closing price since May 1, 2009. Brent crude was last down $1.60 to $58 per barrel, after hitting a session low of $57.61, the lowest since May 26, 2009.



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Prices rose early on concerns about the damage in Libya, after an oil official said the country's two largest ports, Es Sider and Ras Lanuf, were being kept shut. But prices retreated as investors concluded that disruptions in Libya will not remove much supply from the global market.

"Every time the market tries to pick itself up, it's just another wave of selling," said Gene McGillian, senior analyst at Tradition Energy in Stamford, Connecticut. He said the market's concerns about oversupply are not going away.