China National Petroleum Corporation (CNPC) has backed out of a $4.7bn contract with Iran to develop phase 11 of the offshore South Pars gas project, according to Iranian state media.

Mehr news agency reported that CNPC had pulled its workers out of Assaluyeh, Iran’s Gulf coast hub for the South Pars projects.

CNPC won the contract from National Iranian Oil Company (NIOC) in 2009, replacing an original deal with French engineering group Total.

Iran’s Oil Ministry has blamed the Chinese group for delays in buying equipment and starting preparatory works, while NIOC has said domestic companies are on standby to replace CNPC as the development partner.

The project is planned to increase the South Pars field’s gas production by 2 billion cubic feet a day and its natural gas liquids (NGL) output by 70,000 barrels a day.