Iran nuclear talks fail to reach deal, France pushes back

* Iran, six powers to meet again on Nov. 20

* France's Fabius: Paris won't accept "fool's game" with Iran

* Kerry plays down signs of divisions among Western allies

* Iran says hopes for nuclear deal later this month

By Stephanie Nebehay and Lesley Wroughton

GENEVA, Nov 10 (Reuters) - Iran and six world powers failed in marathon talks to clinch a deal to curb Tehran's nuclear program but said differences had narrowed and they would resume negotiations in 10 days in a fresh bid to end the decade-old standoff.

But clear divisions emerged among the U.S. and European allies on the final day of the talks as France hinted that the proposal under discussion did not sufficiently neutralize the threat of an Iranian nuclear bomb. Iran is hoping for a deal that would ease the international sanctions that have frozen its assets around the world and prevented it from selling its oil.

It is ultimately the Americans and Iranians, who have not had formal diplomatic ties for more than three decades, who have the power to make or break an agreement.

But on Saturday the attention suddenly turned to the French after Foreign Minister Laurent Fabius told France Inter radio that Paris could not accept a "fool's game" - in other words, a weak deal with Iran.

"From the start, France wanted an agreement to the important question of Iran's nuclear programme," Fabius told reporters after the meeting, which ran into the early hours of Sunday.

"The Geneva meeting allowed us to advance but we were not able to conclude because there are still some questions to be addressed," Fabius said.

Fabius' pointed remarks rankled others in the Western camp. One diplomat close to the negotiations said the French were trying to upstage the other powers and were causing unnecessary trouble for participants in the talks, which are aimed at securing a deal with Iran that has eluded the West for a decade.

"The Americans, the EU and the Iranians have been working intensively together for months on this proposal and this is nothing more than an attempt by Fabius to insert himself into relevance late in the negotiations," the diplomat told Reuters, speaking on condition of anonymity.

KERRY SEES UNITY

Kerry played down suggestions of a rift, saying, "I think tonight there is a unity in our position and a unity in the purpose as we leave here."

European Union (EU) foreign policy chief Catherine Ashton said senior political officials from Iran and the five permanent U.N. Security Council members plus Germany would meet again on Nov. 20 to work on a deal.

Kerry told reporters that an agreement could be within reach.