Iran is likely to start exports of liquefied natural gas (LNG) supplies in less than two years, Iran LNG President Ali Khayrandish said.
Iranian officials say that sanctions preventing western liquefaction technology from being supplied to Iran are having no impact on its plans and that it can manage without external project funding.
"The project is now 53-54 per cent complete and we expect to send a first cargo in Q1 2013," Khayrandish said at a conference in London.
"Our country has enough revenue for this project, but if a new recession comes and we lose some money from petroleum exports, then it could lead to delays."
A sustained fall in oil prices could cut OPEC-member Iran's export revenues and delay the project, he said.
India's Oil and Natural Gas Corp. has since been linked to gas export projects in Iran.
Iran LNG is the most advanced project and Indonesia said last month it was in talks to buy output from Iran LNG from 2013.
Iran, which sits on the world's second largest reserves of both oil and gas, is facing US sanctions over its civilian nuclear program.
Iranian officials have dismissed US sanctions as inefficient, saying that they are finding Asian partners instead. A large number of Chinese, Indian and other Asian firms have negotiated or signed up to oil and gas deals with Iran.
In a recent case, Iran signed gas deals worth $14 billion with Malaysia's SKS Group in December 2008, which included a contract to build an LNG plant.
Following US pressures on companies to stop business with Tehran, many western companies decided to do a balancing act. They tried to maintain their presence in Iran, which is rich in oil and gas, but not getting into big deals that could endanger their interests in the US.
Yet, after oil giants in the West witnessed that their absence in big deals has provided Chinese, Indian and Russian companies with excellent opportunities to sign up to an increasing number of energy projects and earn billions of dollars, they started showing increasing interest to invest or expand work in Iran.
Some European states have also voiced interest in investment in Iran's energy sector after a gas deal was signed between Iran and Switzerland three years ago regardless of the US sanctions.
The National Iranian Gas Export Company and Switzerland's Elektrizitaetsgesellschaft Laufenburg signed a 25-year deal in March 2008 for the delivery of 5.5 billion cubic meters of gas per year.
The biggest recent deal, worth €100m ($147m, £80m), was signed by Steiner Prematechnik Gastec, the German engineering company, in 2009 to build equipment for three gas conversion plants in Iran.
Iranian officials have always stressed that the International and unilateral sanctions against Iran have had no result but inflicting damage on the European companies.