"The payment will be in at least three installments. The modalities of installments and the route are being worked out," he said.
The dues to Iran on crude oil that refiners buy have accumulated as Western sanctions blocked payment routes since 2013.
About 45 per cent of the oil import bill is paid in rupees in a Uco Bank branch and the rest has accumulated.
The official said the payment to Iran can be either through Reserve Bank of India (RBI) - in that case refiners will hand over the money to the central bank which will then do the onward transmission to Iran, or through a gateway notified by the government.
Iran will use the rupee payments to settle bills for goods and commodities it imports from India.
The official said the new account will be different from the Uco Bank account which is a non-interest bearing account. "They want the payments to be made to an interest-bearing account."
Since February 2013, refiners like Mangalore Refinery and Petrochemicals (MRPL) and Essar Oil have been paying 45 per cent of payment due on purchase of crude oil from Iran in rupees through Uco Bank, Kolkata.
The outstanding has since climbed to over USD 6.5 billion.
Essar Oil owes USD 3.34 billion, MRPL (USD 2.49 billion) and Indian Oil Corp (USD 581 million) to Iran. HPCL-Mittal Energy Ltd (HMEL) owes USD 97 million and Hindustan Petroleum Corp Ltd (HPCL) another USD 29 million.
Besides, about Rs 17,000 crore was lying in Iranian account with Uco Bank.
"What is due to them, must be paid to them. It will not be one single bullet of USD 6.5 billion. It will be (in) tranches. They also don't want as bullet, they also want it in some kind of tranches. So we are working out with Iran," he said.
