French telecoms giant Altice has acquired a 12.1% stake in BT Group for £2.2bn, becoming the British telco giant’s largest shareholder.

Altice said it does not plan to make a takeover bid for BT and that it is backing the company’s ambition to build a nationwide fibre broadband network.

Its stake puts it ahead of the previous largest shareholder Deutsche Telekom, which based on recent filings holds a 12.06% stake in BT. Deutsche Telekom also has a seat on the BT board and experts expect Altice will also seek representation.

Altice, the second-largest telecoms company in France, is owned by French-Israeli billionaire Patrick Drahi, who founded the company in 2001. It operates fibre and mobile networks serving more than 40 million customers in the US, France, Portugal and Israel.

Drahi made the stake in BT via the newly created investment vehicle Altice UK.

“Altice holds the board and management team of BT in high regard and is supportive of their strategy,” Altice UK said in a statement.

The company added: “Altice UK has informed the BT board that it does not intend to make a takeover offer for BT.”

BT is the biggest broadband and mobile operator in Britain and plans to extend next-generation full-fibre and gigabit-speed broadband to 25 million homes and businesses by 2026.

It has been seeking an extra £3bn from investors to help fund this venture, on top of the £12bn already pledged to help the UK bring its full-fibre broadband network up to the same standard of countries such as Spain.

In the 2019 general election, Prime Minister Boris Johnson promised gigabit speeds for “every home and business” by 2025.

“We welcome all investors who recognize the long-term value of our business and the important role it plays in the UK. We are making good progress in delivering our strategy and plan,” said BT Group in a short statement.

News of Altice’s investment sent BT shares up by 4% on Thursday.