"The Iranians want to go ahead with a smaller project than the one we had envisaged and therefore we are having discussions about whether we stay involved in the longer term," Mr Aiken said.

In the interview, Mr Aiken said he wasn't convinced that the project, which is almost half the size of BHPB's $US1 billion development proposal, would add any value for its shareholders. He added that a definitive decision on whether to stay involved would be made "in the next couple months."

Earlier this year, the state-owned National Iranian Oil Company signed a contract with Iran Petro-Development to redevelop the fields in order to raise production from 40,000 barrels of oil per day (bopd) to 109,000 bopd.

Under terms of the agreement, Iran Petro-Development would make the necessary investment in the fields, which would most likely include the participation of a foreign partner such as BHP Billiton.

Mr Aiken told the newspaper that even if the deal fell through, this would not signal the company's exit from the Islamic nation of 70 million people. The company would still be involved in a potential pipeline that will take gas to Pakistan and India.