LONDON (Reuters) - OPEC has no power over many of the factors buffeting oil markets and the group is worried by record high prices that are threatening the world economy and future demand growth, OPEC ministers said on Tuesday.

“Please don’t blame us for $93 oil,” Qatari Oil Minister Abdullah al-Attiyah told reporters on the fringes of an international energy conference.

“The market is out of control.”

OPEC President Mohammed bin Dhaen al-Hamli reiterated OPEC would always step in to meet supply shortfalls, but a 34 percent surge in the oil price since mid-August was driven by a flood of speculative investment and international political tensions.

“The market is increasingly driven by forces beyond OPEC’s control, by geopolitical events and the growing influence of financial investors,” said Hamli, who is also UAE oil minister.

“We are of course concerned about high oil prices.”

“We will do what we can, mainly responding to changing demand fundamentals.”

OPEC oil ministers will meet for informal talks as OPEC heads of state gather in Riyadh in mid-November.

Ministers have ruled out any policy decision at those talks -- OPEC has already agreed to add 500,000 barrels per day of oil from November 1. Hamli repeated the line that an output increase was not on the agenda in Riyadh.

OPEC’s next formal meeting is on December 5 in Abu Dhabi.

“We are monitoring the situation closely. We will review the situation there and then,” Hamli said of the December talks.

“We have to stay alert. If the market needs more oil, we will supply it,” he added.

The 10 OPEC members subject to output restraint -- all except Iraq and Angola -- will aim to ship 27.253 million bpd of oil onto the 86 million bpd global market from November 1.

If Iraq and Angola’s production are added in, OPEC will be pumping nearer 31 million bpd.

But consumer nations, including top energy user the United States, are calling for more.

“If oil is going up and keeping at this level it may hurt the economy, especially non-oil producing developing countries,” said Nobuo Tanaka, executive director of the International Energy Agency that advises industrialized consumer nations.