VIENNA Saudi Oil Minister Ali al-Naimi said on Wednesday that he had no doubt OPEC would raise output some time during the third quarter.

But the minister, the most influential in the cartel, said he was not certain yet at what point during that period the extra crude would be needed, Reuters reported.

"I have no doubt we are going to release more oil. It's just a question of July, August or September and how much volume," he told reporters.

But Iranian Oil Minister Bijan Zangeneh said it was too early to say whether producers would need to pump more crude or not.

"I don't know, it depends on many things like the level of stocks, the level of prices, the economic growth rate, non-OPEC production," said Zangeneh.

"We need to study the market in July and at that time we can decide. Now we cannot predict."

The ministers were speaking after OPEC's Tuesday decision to leave output unchanged and hold an emergency session on July 3 to address the stoppage by Iraq of its 2.1 million barrels daily of UN-administered sales.

Iraq has said it will remain out of the market for at least the duration of the one-month extension by the UN of its oil-for-food exchange with Baghdad. The world body is considering revised sanctions against Iraq.

Naimi, who has pledged not to allow a shortage develop in world oil markets, said the Iraqi outage was not a concern to him.

"Saudi Arabia alone could easily handle that," he said. On Tuesday he said Riyadh had 2.5 million barrels a day of spare capacity that could be brought completely onstream within 90 days.

Naimi said oil markets were well supplied for the time being.

"Refiners are making a killing in the U.S. because of good crude stocks and the delta between products and crude oil," he said.