In morning trade, New York's main oil futures contract, light sweet crude for delivery in May, tumbled 1.14 dollars to 104.48 dollars per barrel.
The contract closed at 105.62 dollars per barrel during floor trading on Friday at the New York Mercantile Exchange.
Brent North Sea crude for May delivery fell 87 cents to 102.90 dollars a barrel, after settling at 103.77 in London on Friday.
Oil prices fell Friday after the US Commerce Department reported that the US economy, the world's biggest oil consumer, grew at a tepid 0.6 per cent in the fourth quarter last year.
Economic momentum slowed during late 2007 despite the US Federal Reserve's interest rate cuts in a bid to bolster a slowing economy and a stressed housing market.