OVL has offered to invest about $5.8 billion in developing the Farzad-B gas field and another $5 billion to build a liquefied natural gas export facility, he said.
Iran wants a high price of the natural gas, making the investment practically unviable.
"We will get the project the day we accept their conditions. But for me to go ahead and make such investments, it has to bring reasonable returns and making economic sense," he said without elaborating.
Iran had earlier this year signed an initial pact with Russia's Gazprom for developing the OVL-discovered gas field of Farzad B but has kept the door open for awarding it to the Indian firm.
"We have given them our best offer. Now, it is up to them to agree or not agree," Verma said.
Iran retaliated by first cutting by one-third the time it gave to Indian refiners to pay for oil they buy from it as also raising ship freight rates, and then by signing a memorandum of understanding (MoU) with Russian gas monopoly Gazprom.
Farzad B was discovered by OVL in the Farsi block about 10 years ago. The project has so far cost the OVL-led consortium, which also includes Oil India Ltd and Indian Oil Corp (IOC), over USD 80 million.
The field in the Farsi block has an in-place gas reserve of 21.7 tcf, of which 12.5 tcf are recoverable. New Delhi is keen that the gas from the field comes to India to feed the vast energy needs.
Sources said Indian refiners have cut oil imports from Iran by a fifth to 190,000 barrels per day (bpd) in 2017-18 from 240,000 bpd in the previous fiscal.
Iran, India's third biggest oil supplier, used to give a 90-day credit period to refiners like Indian Oil Corp (IOC) and Mangalore Refinery and Petrochemicals Ltd (MRPL) to pay for the oil they would buy from it.
Now, Tehran has reduced this to 60 days, essentially meaning that IOC and MRPL would have to pay for the oil they buy from Iran in 60 days instead of previous liberal term of 90 days, sources said.
Iran oil sale terms were the most attractive for Indian refiners. Besides, a liberal credit period, it also shipped the oil to India for a nominal 20 per cent of normal ocean freight.
Other Middle-East sellers offer not more than 15-day credit period.
Sources said National Iranian Oil Co (NIOC) has also decided to cut the discount it offers to Indian buyers on freight from 80 per cent to about 60 per cent.