Opec ministers will hold an emergency meeting on Sunday in order to decide whether to boost oil exports, sources from the oil producers' cartel have said.

The meeting will come exactly a month after the cartel risked angering consumer countries by agreeing to slash output.

Since then, oil prices have soared to above $30 a barrel due to the paralysis of Venezuela's energy industry.

A possible war with Iraq also threatens to disrupt supplies from the Mideast, putting further upward pressure on prices.

US oil stocks are almost at their lowest level for 26 years - a potentially worrying situation for a country about to go to war.

Controlling power

The 11 Opec members try to keep the price of crude oil between $22 and $28 a barrel by controlling the amount of oil they release into the global marketplace.

Ministers have been discussing how to bring the oil price back into this range over the telephone.

But they have reportedly failed to agree on the amount by which to increase production, meaning that a full ministerial meeting has become necessary.

Saudi Arabia is thought to be pressing for a substantial cut of two million barrels a day, whereas other members fear this could be too drastic.

Oil prices were already falling in both the US and London on expectations of increased output.

London's Brent oil benchmark closed 51 cents lower at $29.69 a barrel, while US crude fell 98 cents to $30.9 by 1700 GMT.