New Delhi, Jan. 13: State-owned Indian Oil (IOC), Hindustan Petroleum (HPCL) and Bharat Petroleum (BPCL) are planning to jointly set up a mega refinery on the west coast.

However, it is unclear whether it would be larger than Reliance Industries' (RIL) Jamnagar refinery, globally the largest in terms of a refining capacity of 1.24 million barrels per day.

"The plan has gone beyond thinking stage and is now under conception. The size, investment and configuration are all under works," Sanjiv Singh, director (refineries) of IOC, said.

RIL holds the distinction of building the largest refinery till now. It built its first refinery at Jamnagar in Gujarat with a capacity of 27 million tonnes (mt), which was subsequently expanded to 33mt. It built another unit adjacent to it for exports with a capacity of 29mt.

The refinery being planned will cost Rs 2,500 crore per million tonnes, he said.

Fifteen million tonnes a year is the biggest refinery any public sector unit has set up in one stage. IOC has started phased commissioning of its 15mt unit at Paradip in Odisha.

Industry officials said large refineries set up at coastal areas help to cut down inventory losses as they do not have to transport crude over land to the refinery set up in places such as Panipat or Mathura.

They said state-owned companies should be logically looking at a minimum capacity of 30mt and going up to 45mt with their combined strength, when RIL can operate a 62mt facility in Gujarat.

Oil minister Dharmendra Pradhan had last month asked three state-run refiners to get ready to set up the largest refining and petrochemicals complex in the public sector before 2017-end in coastal Maharashtra.