New York: Oil jumped nearly 4 per cent on Monday as the world's largest producers gathered in Algeria to discuss ways to support prices, with nervous trade driving volatility to its highest since a similar meeting to freeze output in April in Doha which failed.

The Organisation of the Petroleum Exporting Countries and other exporters led by No 1 producer Russia are meeting informally on the sidelines of the International Energy Forum in Algeria from September 26-28 to discuss steps to tackle a price-eroding glut of crude.

Key OPEC member Iran, the fourth largest crude exporter which is still trying to recapture output before Western sanctions in 2012, downplayed the chances of a deal while some OPEC members remained hopeful.

Brent crude futures were up $1.75, or 3.8 per cent, at $47.64 a barrel by 3.19pm GMT. US West Texas Intermediate (WTI) crude futures rose $1.65, or 3.7 per cent, to $46.13.

Implied volatility, a gauge of how much oil prices move, was at its highest since April 18, when the meeting in Doha among OPEC members to discuss an output freeze ended in an impasse, leaving crude at just above $40.

Scepticism about any deal being reached prompted money managers to cut their bullish bets on US crude futures to a one-month low last week, when prices fell by nearly 5 per cent.

Some analysts believe implementation of a freeze will only be after OPEC's all-important policy meeting in Vienna in November. Until then, the group and non-members, including Russia and No 1 oil consumer the United States, are likely to ramp up output.

"While we look for both Russia and the OPEC membership to continue to talk up the market via bullish hype whenever crude prices decline by a few dollars a barrel, we are maintaining a view that this type of artificial price support is simply delaying the inevitable by allowing non-OPEC production, especially from US shale producers, to recover further," said Jim Ritterbusch of Chicago-based oil markets consultancy Ritterbusch & Associates.

OPEC pumped near a multi-year high of 33.24 million barrels per day in August, data showed. Russian production hit record highs of 11.75 million bpd last week. US output has fallen this year but its oil rig count, which signals future production, has risen for 12 of the past 13 weeks.

Unplanned outages across OPEC still amount to around 2 million bpd, making it hard for members to agree to a freeze, SEB commodities strategist Bjarne Schieldrop said.

"They will come away with nothing, because it is too difficult. How can they decide a freeze when Libya is on the doorstep of returning production, or Nigeria for that matter?" Schieldrop said.