"There has been no shortage of oil in the market. Producers have been able to meet consumer needs," Abdullah al-Badri told an energy conference. "We also see this as being the case for the rest of 2012 and the foreseeable future."

Oil prices surged in March to $128 a barrel, the highest level since 2008, because of concern about possible supply shortages. Prices have since fallen back and Brent crude was trading around $118 on Thursday.

"Today the price continues to be driven by excessive speculation," Badri said.

OPEC at a meeting in December set a target to produce 30 million barrels per day, settling an argument which broke out in 2011 after Iran and other members opposed a Saudi-led plan to raise OPEC's production ceiling.

Output has remained above the target all year as Libyan supply recovered after being virtually shut down during the 2011 uprising against Muammar Gaddafi's rule.

The extra oil is filling gaps caused by an unusually large number of supply outages globally, which have also helped support prices. Supply breaks were running at nearly 1.3 million bpd as of early April.

The additional supply has also offset a decline in exports from Iran, which is facing stiffening western sanctions over its disputed nuclear energy program.

Iranian oil exports were running at between 200,000 and 300,000 barrels per day below last year's level, Maria van der Hoeven, head of the International Energy Agency, told Thursday's conference.

Iranian officials have said the country exported an average of 2.2 million barrels a day last year.

April supply from the 12-member Organization of the Petroleum Exporting Countries ran at 31.75 million barrels per day (bpd), the highest since September 2008, which was shortly before it agreed to a series of supply curbs to combat recession and collapsing demand, based on Reuters surveys.