"We have scheduled for the last exchange of papers on Tuesday and afterwards everything will be finished," National Iranian Oil Co director for investment Hojatollah Ghanimifard told Platts in an interview.

Ghanimifard added the meeting next week would provide Pakistani officials with a "resolution of the NIOC board of director's and take Pakistan's comfort (guarantee) letter."

"As soon as these two are exchanged in Tehran, the contract will become effective," Ghanimifard said.

He added Iran received a sovereign guarantee agreement from Pakistan's government last Friday, contracting 750,000 Mcf/d of gas imports for 25-years.

The agreement is renewable for a further five years and includes a provision to expand the volume imported to 1 Bcf/d.

First delivery will take place in four-and-a-half years, Ghanimifard said without specifying a volume, gradually increasing to "full delivery of 21.5 million cubic meters per day of natural gas...from the southern offshore South Pars gas field."

The NIOC and Pakistan's Interstate Pipeline Co signed a gas sales and purchase agreement in June last year under which Pakistan agreed Iranian gas based on the Japanese crude cocktail price.

Pakistan will pay $7/MMBtu if the Japan Crude Cocktail price is $50/barrel, $9.40/MMBtu and $13/MMBtu when the JCC price touches $70/b and $100/b, respectively.

The gas will help Pakistan save $1 billion per year on oil imports, Pakistan's oil ministry has previously said.

The Iran-Pakistan gas pipeline project was first touted in the 1990s and included India as a partner.

Under the original agreement, Iran, which holds the world's second largest gas reserves behind Russia, planned to export 2.12 Bcf/d of natural gas to be split evenly between the two countries.

The project, however, experienced repeated delays over several issues, including disputes between India and Pakistan on transit charges and security provisions. There was also speculation that the US had put pressure on India to withdraw from the project.

Pakistan and Iran, meanwhile, say they have agreed to transport the gas to India if India decides to rejoin the project.

--Aresu Eqbali, newsdesk@platts.com