RIYADH, Saudi Arabia - OPEC will study the weak U.S. dollar on the oil cartel's earnings and investigate the possibility of a currency basket, Iran's oil minister said Sunday.

"We have agreed to set up a committee consisting of oil and finance ministers from OPEC countries to study the impact of the dollar on oil prices,'' Gholam Hussein Nozari told Dow Jones Newswires at a rare heads-of-state OPEC summit.

Iraqi Oil Minister Hussein al-Shahristani also confirmed the formation of a committee, which will "submit to OPEC its recommendation on a basket of currencies that OPEC members will deal with.'' He did not give a timeline for the recommendation.

Though a final statement issued at the end of the OPEC summit on Sunday did not specifically mention the dollar or a committee, it did say the oil-producing group would look into ways of improving financial co-operation.

OPEC will "study ways and means of enhancing financial co-operation among OPEC . . . including proposals by some of the heads of state and governments in their statements to the summit,'' OPEC Secretary General Abdalla Salem el-Badri said, reading from the statement.

Iran and Venezuela have been pressuring the Organization of Petroleum Exporting Countries to study the affect of the falling dollar. But the suggestions were met with resistance from other OPEC members, including Saudi Arabia's foreign minister who warned Friday that even talking publicly about the currency's decline could further hurt its value.

Oil is priced in U.S. dollars on the world market, and its depreciation has concerned oil producers because it has contributed to rising crude prices and has eroded the value of their dollar reserves. Cartel officials have resisted pressure to increase oil production to ease prices.

During his final remarks, el-Badri stressed he was committed to supply -- but did not mention changing oil outputs, as expected.

"We affirm our commitment . . . to continue providing adequate, timely, efficient, economic and reliable petroleum supplies to the world market,'' he said.

The run-up to the meeting was dominated by speculation over whether OPEC would raise production following recent oil-price increases that have closed in on US$100.

U.S. Energy Secretary Samuel Bodman has called on OPEC to increase production earlier this week, but cartel officials have said they will hold off any decision until the group meets next month in Abu Dhabi, United Arab Emirates.

They have also cast doubt on the effect any output hike would have on oil prices, saying the recent rise has been driven by the falling dollar and financial speculation by investment funds, rather than any supply shortage.

The meeting in Riyadh was the third full OPEC summit since the organization was created in 1960. Libya's oil policy head, Shokri Ghanem, confirmed to Dow Jones that Libya is to host the next heads of state summit in 2012.