Marco Dunand, chairman and co-founder of Swiss-based Mercuria Energy Group, said prices could easily jump back toward the record highs seen in 2008 "and potentially even higher if we had a major crisis".

"I don't want to over-hype things, but there are scenarios under which (crude oil) could go above $150 without a doubt, and those scenarios are to do with stability in the Middle East if things start spreading," Dunand told Reuters in an interview.

"The risk of our forecast is on the upside, and there's a possibility that we may see $150 within the next few months. But I would give it a 20 percent possibility."

Crude oil prices rose above $147 per barrel in July 2008 as worries over a potential shortage pulled in a wave of new investors.

Prices plunged as recession took hold but have since recovered. North Sea Brent futures hit $108.70 this week, their highest since September 2008.

Markets are riding up on worries over the security of supplies from the Middle East and North Africa, which pumps around a third of the world's oil, as unrest sweeps through the region.

Dunand said he thought the potential equilibrium price for crude oil was close to $100 per barrel, "between $90 and $110".

"The risk is on the upside because of the hotspots of uncertainty created around the globe," he said.

"We could easily see a spike back toward the highs we have seen and potentially even higher if we had a major crisis."

Mercuria is one of the five biggest independent energy traders and operates in more than 50 countries.

Dunand said the revolt in Libya was having a serious impact on oil because its oil fields, which export around 1.3 million barrel per day (bpd), were close to European markets.

Libyan ruler Muammar Qaddafi is struggling to crush a revolt against his 41 years of rule in Africa's third-largest oil producer. Italy's Foreign Minister said on Wednesday up to 1,000 people had been killed in the Libyan unrest.

"Of the various countries that we have seen so far going through turmoil, Libya is the one which could maybe have the most impact," Dunand said. "It only takes a very short time for Libyan oil to come into the Mediterranean refiners.

"Whether you could have production halted for a few hours, or a few days, or possibly longer is anybody's guess. There is now a risk of greater volatility," he said.

"I think we are going to ride into a volatile and potentially dangerous situation over the next few months."

Dunand said unrest elsewhere in the Middle East was also a concern, particularly the turmoil in Bahrain.

"It is very difficult to know how things can escalate. The perception for the time being is that the Middle East is a little more stable than North Africa. But can anyone say for sure that there will be no problems there? Obviously not."