Oil prices fell to just below $90 a barrel this morning after sea fog in the United States that had been halting crude imports lifted briefly.
US light crude for March delivery fell 30 cents to $89.72 a barrel, partially erasing yesterday's $1.06 gains, which saw oil closing at $90.02 a barrel.
London Brent crude fell 15 cents to $90.32.
Eight ships, include five tankers, made it into the Houston area, the biggest American petrochemical complex, before pilots closed the waterway again due to the lack of visibility.
Fog is an intermittent problem in winter along the Gulf Coast, a major US refining centre that accounts for 13.5 per cent of the country's refining capacity.
Disruptions to imports in the past have led to sharp draw-downs in commercial crude stock levels or forced refiners to cut production.