Reports in Al-Jazeera news agency and India’s Business Times, both citing “senior [Indian] industry sources”, say an Indian delegation was unable to get the deal going.

“We are extremely disappointed," Al-Jazeera’s source said.

"Their offer price was unacceptable. We cannot buy LNG at that price. It was much higher than the US$2.53 per million British thermal unit (mBtu) [that India was prepared to pay].”

Also up in the air are stakes in Iran’s Yadavaran and, possibly, Juffair fields. Iran had earlier made purchase of gas conditional to award of exploration blocks to India.

“[Iranian] law does not give equity to foreign companies in oil and gas fields," the insider told Al-Jazeera.

"What they proposed was a fixed rate of return on the capital Indian companies would be investing in developing the oil fields. With that return, they may choose to buy oil from Iran. This is certainly not an attractive proposition.”

According to a Business India report, Iran had tried to sweeten the deal in order to persuade India to sign.

“Iran has offered 20% stake in Yadavaran, which has potential to produce 300,000 to 400,000 barrels of oil an annum, under a service or buyback contract. But in case we agree to take 7.5 million tonnes of LNG, Iran has offered to give more than 50% or even full stake in a smaller field at Juffair,” Business India quoted from an unnamed source.

“The next round of talks will be held during petroleum minister Mani Shankar Aiyar’s visit to attend a seminar in Iran next month,” it said.