By GEORGE JAHN
The Associated Press
Friday, June 22, 2007; 8:13 PM

VIENNA, Austria -- Key U.S. allies are debating the idea of a nuclear compromise with Iran that would call for only a partial freeze of Tehran's uranium enrichment program _ a stance that could put them at odds with Washington, officials said Friday.

The officials _ U.S. and European diplomats and government employees _ told The Associated Press that the deliberations among senior British, French and German decision-makers were only preliminary and that no conclusions had been drawn.

Germany was supportive, France opposed and Britain noncommittal, they said.

"Nothing is on paper," said one European diplomat, describing the tentative plan as a "freeze for peace."

With the United States continuing to insist on a full enrichment freeze, the talks could strain the U.S.-led attempt to show unity on the issue or even push Washington to settle for less than it has been demanding.

For the European allies, a compromise would placate important European Union members Italy and Spain and some smaller countries looking for more flexibility in dealing with Iran.

An American official said "there is some truth" to the reports of the discussions among the British, French and Germans. "We're still very skittish on that," the official said.

The U.S. has allied with Britain, France and Germany in a four-year campaign to contain what they fear are Iranian ambitions to develop nuclear weapons.

Backed by U.N. Security Council resolutions, they demanded Tehran abandon uranium enrichment, a process that can provide material for nuclear warheads. Iran insists it wants only to produce fuel for nuclear reactors that would generate electricity.

The United States' support from permanent Security Council members Britain and France, in particular, has been key. The council has passed two sets of sanctions in the last half year against Iran in reaction to Tehran's rejection of council demands for an enrichment freeze.

With permanent members Russia and China only reluctantly backing sanctions and only in weakened form, the loss of European support would leave Washington with the hard choice of either backing away from its insistence on a full enrichment freeze or being isolated.

The officials spoke amid signs Tehran might be leaning toward concessions, perhaps as a way to weaken the international pressure. The head of the U.N. nuclear watchdog agency said the Islamic Republic had agreed to provide him with answers on past suspicious atomic activities within two months.

Beside demanding an enrichment freeze _ and a stop to construction of a plutonium-producing reactor _ the Security Council has called on Iran to provide answers to the International Atomic Energy Agency on activities that could be linked to a weapons program.

While the key issue remains enrichment, any follow-through by Iran on its decision to share sensitive information with the IAEA could feed sentiment for a compromise that would allow it to retain some elements of its enrichment program.

The Iranian proposal, to IAEA chief Mohamed ElBaradei, came on the eve of a new round of talks between Larijani and Javier Solana, the EU's foreign policy chief.

But Larijani suggested the offer was conditional on reaching a "political understanding" with the EU representative. That was apparent shorthand for a broader deal that would allow for the start of negotiations between Iran and the five permanent council members and Germany on nuclear issues without the present precondition of a complete enrichment freeze.

Officials told AP last month that Iran had considered stopping some _ but not all _ of its enriched-uranium producing centrifuges last year in exchange for negotiations. But the U.S., Britain and France continued to insist on a full freeze.

The issue gained in importance last month when ElBaradei sent a report to the Security Council that says Iran has expanded its enrichment activities instead of freezing them _ a finding that could act as a trigger for a third set of sanctions.

The compromise being discussed by the Europeans derives from a Swiss proposal under which Iran would not expand its enrichment work in exchange for the Security Council not imposing further sanctions while diplomats pursue a resumption of formal negotiations.

Multilateral talks with Iran broke off in August 2005 after Tehran rejected an offer of political and economic incentives in exchange for a pledge for long-term suspension and resumed its enrichment activities.

Since then, Iran has repeatedly said an enrichment freeze was out of the question while the six world powers insisted they would accept nothing less as a condition for resuming negotiations.

"Our intention is to continue exploring the possibility of launching formal negotiations," Solana's spokeswoman, Cristina Gallach, said of Saturday's planned meeting with Larijani in Lisbon, Portugal.

But she added, referring to Iran's enrichment program, "They have to comply with U.N. resolutions."