Opec: five facts

Opec was founded in Baghdad in 1960 The five founder members were Iran, Iraq, Kuwait, Saudi Arabia and Venezuela Since 1975, Opec has been based in Vienna Current members also include Algeria, Libya, Nigeria, Indonesia, Qatar and the United Arab Emirates Two countries, Ecuador and Gabon, joined Opec in the 1970s and left in the 1990s

Opec officials had previously said they wanted prices to remain within a $22-28 a barrel range and would boost or cut supplies to help the price stay within this range.

However, managing the market to such a fine degree is proving to be difficult.

Any production increase would take several weeks to be felt in the consumer countries, analysts say.

Saudi's quiet approach

The world's leading oil producer and exporter, Saudi Arabia, has appeared to be in favour of increasing output to help soften prices.

But it has preferred a quiet approach, lifting production only gradually and saying little publicly.

Venezuela has adopted a more confrontational stance and has denied that prices are too high, despite in the past regularly flouting its Opec production quotas and thereby driving down prices.

US criticism

Mr Chavez, who attracted criticism from the US for meeting Iraqi President Saddam Hussein last week, was concluding his tour of Opec states with a visit to Algeria.

The purpose of the 10-nation trip had been to issue invitations to an Opec heads-of-state summit in the Venezuelan capital Caracas in late September.

Analysts have speculated that Saudi Arabia has kept quiet about its oil policy partly because of internal disagreements and partly because it does not want to be seen as out of step with its Opec partners in the run-up to a summit designed to promote unity.