Telecoms giant will face more rivalry from competitors as it is told to open up access to its high-speed network
The proposal is aimed at increasing competition in the "leased-lines" market worth £2bn a year, Ofcom said in a statement on Friday.
Such lines are dedicated, high-speed links used by companies as well as mobile- phone and broadband carriers to transfer data.
BT should give rivals physical access to its fibre-optic cables, allowing competing operators to take direct control of the connection, Ofcom said.
Blow to BT: Ofcom proposes 'dark fibre' rules to let rivals take control of business lines. Also new installation deadlines for Openreach.