US crude oil futures slid as a less optimistic economic outlook from the Federal Reserve outweighed concerns over a potential storm developing in the Atlantic.
US crude for August delivery slid 50 cents, at $75.85 a barrel after falling as low as $75.32 earlier.
In London, ICE Brent futures traded down 31 cents at $75.96 a barrel.
The dollar fell as the US Federal Reserve issued a less optimistic outlook on economic growth yesterday and the euro slipped on renewed worries about Greece's sovereign debt.
Further pressure came after Genscape reported inventories at the key Cushing, Oklahoma crude oil hub rose by 240,000 barrels in the week to June 22.
Traders were also factoring in storm worries after the U.S. National Hurricane Centre said on Thursday that a tropical wave over the Caribbean Sea had about a 40% chance of developing into a tropical depression over the next couple of days.
If the depression develops, a further strengthening could turn it into a named tropical storm, if it does, it will be named Alex.
Most weather models project the current weather disturbance will turn north into the Gulf of Mexico after crossing Mexico's Yucatan Peninsula.
'The dollar has backed off a bit and the storm possibility has been out there and it may have bounced off some technical support also,' said Phil Flynn, analyst at PFGBest Research in Chicago.
Any storm in the region could further complicate BP's clean-up efforts of its massive oil spill and disturb current oil production in operating platforms in the region.
Traders were also keeping close tabs of technical factors, as prices have turned in lower highs and lower lows in the first three days of the week.
Earlier, prices bounced back after data showed the number of US workers filling new applications for unemployment insurance fell more than expected and euro zone industrial orders rose at their fastest pace in 10 years.
The drop in U.S. first-time jobless claims and positive manufacturing data appeared supportive, but not enough to overcome worries arising from the Fed's assessment of the shaky economic recovery that led it to keep interest rates at low levels.
