Dubai: An international arbitration tribunal has been formed to settle a longstanding dispute over a gas deal between the UAE and Iran, a spokesman from the UAE-based Crescent Petroleum told Reuters on Sunday.

"The three-person arbitration tribunal, for the arbitration between Crescent Petroleum and the National Iranian Oil Company (NIOC), has now been officially formed, as per the contract procedures," said a Crescent Petroleum spokesman.

The National Iranian Oil Company (NIOC) and Crescent signed the 25-year gas contract in 2001, with a price linked to oil.

But as oil rallied in the following years, some officials and politicians in Iran called for a revision to the price formula and blamed the price dispute for delivery delays.

Crescent said in July that it was seeking international arbitration for the failure of NIOC to fulfil the contract.

NIOC has yet to complete testing facilities at its offshore Salman field which should have pumped the Islamic Republic's first gas exports to the UAE in December 2005.

"Crescent Petroleum started arbitration in July 2009, seeking specific performance in relation to NIOC's almost four-year delay in providing gas under the 25-year gas supply contract."