During the shutdown HMEL will also carry out work to be able to hook petrochemical units, including a 1.2 million tonnes a year ethylene cracker, sources with knowledge of the plan said.

The 40-day shutdown is expected to start around Jan. 25-26, said one of the sources, adding the company plans to commission petrochemical units in September-October.

The sources declined to be named as they are not authorised to speak to media. HMEL's chief executive Prabh Das said 'no comments' when asked about the shutdown plan.

Indian refiners have turned their focus to raising production of petrochemicals to cater for rising demand and help hedge against lower refined fuel margins.

State-refiner Hindustan Petroleum Corp and Mittal Energy Investments Pvt Ltd own 49 percent stake each in the project.

(Reporting by Nidhi Verma; Editing by Michael Perry)

By Nidhi Verma