Leaders of OPEC countries have ended their summit in Saudi Arabia with a promise to continue providing what they call "sufficient" oil supplies to the world market.

In their closing statement Sunday, OPEC leaders also called for greater financial co-operation among the oil cartel's members.

Several OPEC members also promised to help fight global warming by funding research into climate change. Saudi Arabia pledged 300-million dollars to the effort, while Kuwait and the United Arab Emirates each offered 150-million dollars.

OPEC did not announce any changes to the practice of pricing oil in dollars.

OPEC members Iran and Venezuela have been pushing the cartel to sell oil in currencies other than the dollar, such as the euro. The weakening of the U.S. currency this year has reduced the value of OPEC members' oil exports.

Oil-consuming nations have urged OPEC to increase production to help reduce oil prices, which have soared to almost 100 dollars a barrel in recent weeks.

Ecuadorean President Rafael Correa said at the summit that he backs Venezuelan President Hugo Chavez's call for OPEC to become more political. Saudi King Abdullah rejected the idea Saturday, saying OPEC should not make oil a source of conflict.

Mr. Correa also proposed an environmental tax on richer, oil-consuming nations to pay for the development of alternative fuels.

The two-day OPEC gathering in the Saudi capital, Riyadh, was only the third summit the bloc has held since its founding in 1960.


Some information for this report was provided by AFP, AP and Reuters.