Oil fell for the sixth consecutive session to below $78 a barrel on Monday, as renewed concerns over energy demand? and the outlook for economic growth prompted investors to sell positions.

Oil prices began last week above $80, supported by colder winter weather in the northern hemisphere and an influx of fresh capital from money managers and funds wishing to allocate more money into commodities this year.

But poor company and banking results, including figures from JPMorgan Chase on Friday, concerns about prospects for the macro economy and oil demand, as well as rising temperatures in Europe and the United States pulled prices lower.

U.S. crude for February delivery fell, after touching a three-week intraday low of $77.07.

London Brent crude for March delivery fell.

"Today is likely to be another down day," said Eugen Weinberg, head of commodities analysis at Commerzbank in Frankfurt. "Market sentiment seems to have turned after prices failed to stay above $80 per barrel."

Demand

Crude oil prices have steadily fallen since striking a 15-month intraday high of $83.95 a barrel on Jan 11, dragged down by weak U.S. economic data and fears of a sluggish rebound in demand in the world's largest energy consumer.

Oil is now almost 50 percent below its lifetime high of more than $147 a barrel hit in July 2008.

Cold weather across major oil consuming countries has done little to boost demand, the International Energy Agency said on Friday in a report that trimmed its global demand growth forecast by 20,000 barrels per day.

Qatar's oil minister said on Sunday the market was "well-supplied," while Saudi Arabia's deputy oil minister reiterated that an oil price of between $70 to $80 a barrel was reasonable, adding that it was too early to predict the outcome of OPEC's next meeting in March.

Separately, six major powers discussed on Saturday prospects of further sanctions against Iran over its nuclear program, but China made clear it opposed more punitive action at the moment, participants in the meeting said.

Traders say a raft of Chinese data this week, including fourth-quarter gross domestic product, retail sales and industrial production for December, could offer a lift to crude oil prices.

Investors will also watch U.S. earnings for cues with IBM and Goldman Sachs due to report this week.