Oil prices surged above $143 a barrel for the first time ever Monday, as a weaker dollar spurred investors to seek refuge in dollar-denominated oil futures to hedge against inflation.

'The main factors behind the rise today are the U.S. dollar remains fragile and geopolitical tensions, particularly surrounding Iran,' said David Moore, a commodity strategist at the Commonwealth Bank of Australia in Sydney. 'That's unsettling for the oil market.'

The European Central Bank may raise interest rates at its next meeting on Thursday, a move that would help strengthen the euro against the dollar, Moore said.