JEDDAH, Saudi Arabia, (Reuters) – Saudi Arabia and other producers with oil to spare could agree to raise output at an emergency meeting of energy powers this weekend, but OPEC countries say speculation, not supply, is behind high prices.

Riyadh summoned energy producers, consumers and chief executives from big oil firms to meet on Sunday.

The oil price has more than doubled in a year to almost $140 a barrel, triggering protests from Brussels to Bangkok over record fuel costs that threaten the world’s economy.

Saudi Arabia has said it will raise its crude output to 9.7 million barrels per day (bpd) in July .

The kingdom, the world’s biggest oil exporter, has a policy of keeping a cushion of spare capacity and has said other OPEC members that can bring on extra production quickly would also discuss boosting output to try to tame the oil rally. “The short-term policies to be discussed include the proposal that those OPEC countries that have spare capacity should boost supply, just like Saudi Arabia has announced it will do in July,” a senior Gulf OPEC official told Reuters.

Looking to the longer term, the source also said Saudi Arabia would consider increasing its capacity beyond an existing goal of 12.5 million bpd by the end of next year.

The two other OPEC members with some extra capacity are the United Arab Emirates and Kuwait. Another OPEC delegate said it was not yet clear whether they would join in any output rise.

Kuwaiti Oil Minister Mohammad al-Olaim told Reuters he had no plans to raise output ahead of the talks, but would consider options afterwards.

While consumer nations have said an OPEC output rise would help to calm runaway oil markets, OPEC member countries have repeatedly blamed factors including speculation, a weak dollar and political instability.

“Anything that will add supply to the market is important,” U.S. Energy Secretary Sam Bodman said in Jeddah. He added: “While increases in near term oil production are welcome and necessary, fundamentally the market needs to see investment in increasing the longer term production capability.” But Libya’s top oil official Shokri Ghanem said the market had more than enough crude. “There’s oversupply in the market. We believe the prices are high, but it’s not because of supply and demand,” he said, adding he did not expect concrete steps at Sunday’s meeting. “You can’t get any decision on important matters in the energy market in a meeting of three hours,” he said.

Investment funds have pumped billions of dollars into oil and other commodities as they seek to diversify holdings and flee poorly performing asset classes.

U.S. regulator the CFTC, under pressure from lawmakers, has announced a task force to explore commodity activity. It made public this week a deal with its British counterpart to limit trading on oil futures on the London-regulated ICE exchange.

While Riyadh wants action from consumer governments to rein in speculators, Western leaders, including U.S. President George W. Bush, have lobbied heavily for more Middle Eastern crude.

Saudi Arabia’s King Abdullah will open the meeting on Sunday, followed by an address by Britain’s Prime Minister Gordon Brown, the highest-level foreign dignitary to attend.