Openreach is expanding its trial of broadband technology capable of offering speeds of up to 330Mbps.
G.fast technology will be rolled out to 138,000 homes and businesses throughout the UK by the end of March 2017, ISPreview.co.uk reports.
This will be followed by a full-scale commercial deployment later in the year, which should see ten million premises capable of using G.fast by 2020.
Commenting on the rollout, an Openreach spokesperson said: "We’re very excited to be launching the extended pilot, having pioneered G.fast technology in our labs and conducted the world’s largest technical trials.
"The pilot will allow us to test the performance of G.fast, as well as our related processes and systems, at a much larger scale and in a real network environment.
"We expect the pilot to continue into summer 2017.”
G.fast technology has been designed to achieve faster broadband speeds over the existing copper network.
This approach has proved controversial to those who are critical of BT for persisting with copper-based broadband systems.
For instance, Vodafone recently commissioned a study that found that under BT's current plans, the technology will increase ultrafast coverage for households by less than five per cent.
The research by Point Topic also revealed that just 6.5 per cent of households can expect to receive gigabit-capable fibre-optic cables by 2020 unless action is taken.