Patrick Drahi is looking to increase his stake in BT Group plc (LSE:BT.A) as he seeks to extend his influence at the British company, betting its fibre-optic rollout will boost value, three sources familiar with the matter told Reuters. Since the billionaire Altice founder bought a 12.1% stake in BT worth about 2.2 billion pounds ($2.95 billion) on June 10, the British telecom giant?s shares have fallen 15% and are down about 46% over the past five years. The Franco-Israeli entrepreneur?s new vehicle Altice UK is BT?s largest shareholder, ahead of Deutsche Telekom which owns 12.06%. Deutsche Telekom has repeatedly voiced interest in reviewing options for its stake and CEO Tim Hoettges said on Friday he was keeping ?all options open? regarding BT. The three sources, who declined to be named due to the sensitivity of the matter, said any stake-building plan was likely to involve Deutsche Telekom. Altice, BT and Deutsche Telekom declined to comment.