IOC has been gradually raising crude runs at its plants, which plunged to about 39% at the beginning of April when a nationwide coronavirus lockdown hit fuel demand.

Along with its subsidiary Chennai Petroleum Corp, IOC controls about a third of the 5 million barrels per day (bpd) refining capacity in India, where fuel demand in October rose by 2.5%, its first year-on-year rise in eight months.

IOC is operating at full capacity despite lower global refining margins as its "mandate" is to meet the local fuel demand, Vaidya told an oil industry conference on Thursday.

"Refining margins are very poor, in fact they are just not sustainable ... but we are also investing heavily in petrochemicals as a strategy to de-risk the business of low margins," Vaidya said during the ADIPEC event.

Like other Indian refiners, IOC normally operates its plants at more than installed capacity. Vaidya said the situation will return to normal in next quarter.

(Reporting by Nidhi Verma; Editing by Alexander Smith)

By Nidhi Verma