US benchmark West Texas Intermediate for delivery in April slid USD 1.31 to USD 48.69 a barrel.
Brent North Sea crude for April tumbled USD 1.73 to USD 56.80 a barrel.
The euro tumbled yesterday towards a 12-year dollar low, hit by eurozone stimulus, growing US rate hike speculation and Greek debt concerns, dealers said.
The European single currency sank to USD 1.0697 -- the lowest level since mid-April 2003. The region's stock markets also slumped, with London's FTSE 100 closing down 2.52 per cent as shares in energy groups crashed on sliding oil prices.
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Supporting crude prices was unrest in Libya between rival militias and the emergence there of the Islamic State group, analysts said.
Fighting in the north African state, a member of the OPEC oil-producing cartel, has seen output reduced from a high of almost 1.5 million barrels a day to 150,000, according to analysts.
Iraq, another OPEC member, is also battling jihadists who spearheaded a sweeping offensive in June that overran large areas north and west of Baghdad.