Khatam-ol-Anbia Construction Headquarters withdrew from the development plan of South Pars gas field's phases 15 and 16.
This is while the South Pars gas field's phases 15 and 16 development plan is currently over 50 percent complete, the Mehr News Agency reported.
The National Iranian Oil Company has not revealed the reasons behind the issue.
An Iranian consortium led by Khatam-ol-Anbia Construction Headquarters signed the $2 billion worth contract for carrying out the development plan of the mentioned phases in July 2006.
Iran Shipbuilding & Offshore Industries Complex Company (ISOICO) has been introduced as the new leader of the consortium.
Iranian government had approved the allocation of $2 billion for the development of the South Pars gas field's phases 15 and 16 in January.
According to the Islamic Republic of Iran Broadcasting, $500 million of the mentioned amount was allocated to the project out of the Forex fund and $1 billion out of the Oil Ministry's internal financial sources, while a consortium of domestic banks fund the other $500 million.
Development operations of the South Pars phases 15 and 16 started in January 2007.
The project is aimed to produce 50 million cubic meters of refined natural gas per day as well as one million ton of liquefied petroleum gas (LPG) and one million ton of ethane per year. It is estimated that some 75,000 barrels of gas condensates and 400 tons of sulfur will also be extracted from the phases per day.
The South Pars gas field is located on the Persian Gulf. It is the world's largest gas field, shared between Iran and Qatar.
According to International Energy Agency, the field holds an estimated 50.97 trillion cubic meters (1800 trillion cubic feet) of in-situ gas and some 50 billion barrels of condensates.