BT's largest shareholder will join the telecoms giant's board under a new relationship agreement announced on Monday.

Indian billionaire Sunil Bharti Mittal's Bharti Enterprises owns roughly a quarter of BT shares after buying embattled French tycoon Patrick Drahi's stake last year.

BT revealed he would join the group's board as a non-independent, non-executive director, alongside Gopal Vittal, vice chairman and managing director of Bharti Airtel - Bharti Enterprises' telecoms business.

Group chair Adam Crozier told shareholders the pair would bring 'significant experience and global perspectives in the telecoms industry'.

BT said its new relationship agreement means Bharti Global now has the right to nominate two directors to BT's board.

This will stay in place for as long as the organisation holds a stake of at least 20 per cent in BT.

If its stake falls below 20 per cent, it will be allowed to nominate one director as long as it remains above 10 per cent.

Sunil Bharti Mittal said: 'I am delighted to be joining the board of BT, an iconic company delivering critical infrastructure and services for the UK.

'I look forward to working with chairman Adam Crozier, the board and CEO Allison Kirkby to drive forward the strategy to win in the market and deliver world-leading services for BT's customers.'

Gopal Vittal added: 'I look forward to bringing my experience at Airtel to help support BT, whose unique assets and businesses offer valuable opportunities for growth. 

'Airtel and BT have much to learn from and contribute to each other.'

BT shares fell 3.1 per cent to 198.7p in early trading, but have still added more than 35 per cent since the start of 2025.