Robert Lindsay - The Times

Ofcom, the telecoms regulator, today unveiled a plan designed to force BT to rent its "super-fast" fibre optic broadband network to rivals and allow competitors to build their own fibre networks along its telegraph poles and underground ducts.

The move, which has been considered by Ofcom for two years, has emerged after the Conservative Party called on the regulator earlier this year to open BT's underground pipes to rival fibre optic networks. BT has said that it was prepared to do so.

Fibre optic networks can provide speeds of up to ten times faster than traditional copper telephone lines, allowing customers to download broadcast-quality films, high-definition and 3D television and interactive online gaming.

BT is already offering a super-fast service of 50 megabits per second and is rolling out its fibre optic network to cover 40 per cent of the country by 2012. Ofcom said that the former state monopoly should allow rivals to hire this network but that BT could set the price to allow itself a fair return.

Ofcom also said that some 14 per cent of UK households, largely in rural areas, have access to only BT's copper phone line broadband service. As a result, it would impose price caps on BT in these areas "to protect consumers against excessive prices". It said that it believed that competition was effective in the rest of the country so that no regulations would be required.

However, Gordon Brown has proposed a controversial landline levy of £6 a year, or 50p a month, which he detailed yesterday, to ensure that every household in the country, including those in rural areas, has access to super-fast broadband.

Ofcom’s chief executive, Ed Richards, said: "Super-fast broadband is starting to be a reality in the UK, with very significant advances in recent months in the speeds some providers are offering.

"Ofcom’s proposed regulations provide a framework for continued investment, to deliver further roll-out, competition and innovation for consumers."

BT and other companies have until June 1 2012 to respond to Ofcom's proposals.