The 11-member cartel, meeting in Tokyo this week, agreed to maintain production at 21.7 million barrels a day in a bid to keep the price of crude within the organisation's price band of between $US22-$US28 a barrel.

OPEC argued the high price was due to the Iraq issue and not a lack of supply. The cartel's president, Rilwanu Lukman, said supplies would be increased if its benchmark price stay above $28 a barrel for a lengthy period.

OPEC ministers have been reviewing the oil market every three months for the past two years in a bid to avoid the lack of discipline that led to a long-term decline in prices during the 1990s, when crude prices fell to about $US10 a barrel and there was a big decline in the search for new supplies.