Opec would consider raising crude output if the oil price rose to around $90 to $95 a barrel, delegates from the producer group said on Tuesday.

Crude oil futures traded at around $83.80 a barrel on Tuesday, above the $70-$80 mark that Opec's top producer Saudi Arabia and other members have described as fair for both consumers and producers.

"We haven't met to discuss what we will do if the price reaches the $90 to $95 level, but for sure if the price reaches that level we will consider an increase," one delegate told Reuters by telephone.

"I think that if the price was sustained at above $90 to $95 a barrel, then maybe ministers would think about doing something," said another delegate.

Opec has kept its output policy stable for more than a year, but since mid-2009 many countries have been informally raising supply alongside a recovery in prices.

Opec would need to see a sustained rally in oil prices to prompt the group to consider a formal increase in its crude output, Libya's top oil official said on Tuesday.

"What we are seeing in the market is a kind of fluctuation that we cannot build a policy on," Libya's Shokri Ghanem told Reuters.

"It is not a real, continuous trend," he said of the oil price. "We cannot act on (the basis of) one day, one week or even one month."

Opec does not have a price trigger that would prompt the group to consider raising supply, Ghanem said.

When it last met to review its output policy in March, Opec decided to keep policy steady. The group is not scheduled to gather again until October. – Reuters