Panicker will continue to hold his current roles as director and head of refinery, starting his new post from Oct. 3, the company said, praising Fountain's stewardship during his five years in the job.

Fountain said in the statement he was "deeply proud of what has been achieved at Nayara", adding that it was "the right time to hand on to a new leader".

Nayara has been operating in a challenging environment since Western sanctions were imposed on Russia over its invasion of Ukraine in February.

Rosneft owns about 49% of Nayara, while Kesani Enterprises Co Ltd, a consortium led by Trafigura Group and Russia's UCP Investment Group, holds 49.13%.

Nayara has not been sanctioned as part of the international response to what Russia calls a "special military action" in Ukraine, but Rosneft has, and many global oil traders and banks have stopped dealing with the Indian firm due to concern over the sanctions.

Nayara Energy operates the 400,000-barrels per day Vadinar refinery in the western state of Gujarat.

(Reporting by Nidhi Verma; Editing by Helen Popper)