Managing Director of Iran's Pars Oil and Gas Company (POGC) Mousa Souri says all phases of the giant South Pars gas field will definitely go on stream by 2015.

Souri said that every six months from October this year to October 2015, one of the phases of the South Pars gas field will be operational, the official website of Iran's Oil Ministry said.

The official noted that to fulfill the target, around USD 15 billion should be invested in the gas field each year.

Souri also said, once phases 15 and 16 of the South Pars come on stream, about 30 million cubic meters of gas will be added to the country's gas production in the current Iranian year (started March 21), Press TV reported.

The South Pars gas field is shared by Iran and Qatar. The Iranian share, which is divided into 24 phases, has about 14 trillion cubic meters of natural gas (about eight percent of the world's reserves) and more than 18 billion barrels of liquefied natural gas resources.