Dobson was appointed as chairman in April 2016 and previously served as the company's chief executive officer.

There is no set timetable for the succession and Dobson will remain chairman until such time as a successor is appointed, a spokeswomen said in an emailed statement.

(Reporting by Sabahatjahan Contractor in Bengaluru and Pamela Barbaglia; Editing by Sriraj Kalluvila)