• Two sources say at least $10 billion to be unlocked under deal
  • First $3 billion tranche already sent, sources say
  • Deal includes revived economic ties, source says
  • UAE official says Gulf state aims to ease regional tensions
  • Iran sought similar pact with two other Gulf states, source says

DUBAI/LONDON, June 12 (Reuters) - The United Arab Emirates has agreed to unlock billions of dollars for Iran, four sources said, in a tactical shift after weeks of Iranian attacks on the wealthy Gulf Arab state during the U.S.-Israeli war with the Islamic Republic.

Word of the move, which has not been previously reported, coincides with the final stages of broader negotiations between Tehran and Washington on ending the war, talks that diplomats say could involve the release of tens of billions of dollars in Iranian oil revenues frozen in foreign banks under U.S. sanctions.

Two regional sources told Reuters the UAE had agreed to release a total of $10 billion, more than $3 billion of which had already been delivered.

Two other sources with knowledge of the arrangement put the total funds involved at $20 billion, adding that the move had been agreed in return for a halt to Iranian attacks on the UAE. One of the sources with knowledge of the arrangement also said a first tranche of $3 billion had already been made available.

Reuters could not establish whether the funds earmarked for the transfers belong to the UAE or originate in long-blocked Iranian accounts in the UAE banking system, or elsewhere.

But a UAE official, asked to comment on the transfer, said the country was trying to ease tension and foster peace.

"The UAE's foreign policy is guided by promoting de-escalation and reducing tensions across the region, while advancing lasting peace and stability," the official said. "The UAE supports efforts, including those undertaken by the United States, to protect the peoples of the region from the repercussions of conflict."