BT must formally separate from its Openreach network division after failing to address competition concerns, the telecoms watchdog has announced.
Ofcom said it will launch a formal notification to the European Commission over plans to force BT to spin off its Openreach arm, which develops and maintains the UK's main telecoms network used by telephone and broadband providers such as Sky, TalkTalk, Vodafone and BT Consumer.
But the regulator said during this process it still remains "open" to further proposals from BT to meet its "strong competition concerns".
It said: "We are disappointed that BT has not yet come forward with proposals that meet our competition concerns.
"Some progress has been made, but this has not been enough, and action is required now to deliver better outcomes for phone and broadband users."