Sunil Bharti Mittal became BT’s largest shareholder after taking a 24.5pc stake a year ago - Stefan Wermuth/Bloomberg Indian telecoms billionaire Sunil Bharti Mittal has ramped up pressure on BT by taking a seat on the company’s board. Mr Mittal, who became BT’s largest shareholder after taking a 24.5pc stake just over a year ago, has joined the board as a non-independent, non-executive director. Gopal Vittal, vice chairman and managing director of Mr Mittal’s company Bharti Airtel, will also take a sea ...