Oil prices plunged nearly $3 to below $64 a barrel Monday as dismal unemployment figures from the U.S. and Europe last week sparked investor doubts about any nascent economic recovery.

A significant fall in natural gas prices — a likely sign that industries are still struggling and unlikely to add jobs — as well as gains by the U.S. dollar and falling stock markets around the world all helped push energy prices lower.

By mid-afternoon in Europe, benchmark crude for August delivery was down $2.93 to $63.80 a barrel in electronic trading on the New York Mercantile Exchange. Earlier in the session, the contract fell as low as $63.40. It last settled on Thursday at $66.73.

Trading was closed in the U.S. on Friday for the Independence Day holiday.

Oil has tumbled from an eight-month high above $73 a barrel last week after gloomy U.S. consumer confidence and jobs numbers fueled doubts about a rally that has doubled the price of crude since March.

"It's not looking too pretty in terms of economic data," said Christoffer Moltke-Leth, head of sales trading for Saxo Capital Markets in Singapore. "The demand side fear is coming back into play."

A Labor Department report last week showed the U.S. economy lost a larger-than-expected 467,000 jobs in June. The unemployment rate climbed to 9.5 percent, a 26-year high. Unemployment in the 16 countries that use the euro spiked to a 10-year high in May, also at 9.5 percent.

"More and more people are becoming convinced we won't see a full-blown recovery any time soon," Moltke-Leth said. He said he expects the oil price to soon test the $60 a barrel level.