BT had set a launch date of November for the trials of its 8Mbps ADSL broadband Max service, with a full roll-out expected in spring 2006.
The launch of this faster broadband is key for BT as it recovers from the failure of SDSL to capture a large market.
The announcement comes after what Cameron Rejali, managing director, products and strategy for BT Wholesale, described as "highly successful" technical trials which generated positive feedback and high demand from both service providers and end-customers involved in the trial.
BT has already conducted trials of the service in London and Strathclyde. The wider market trial phase will include an initial 25 exchanges, rising to 53 exchanges as the trial progresses. The selected trial exchanges will be located in Greater London, Cornwall, Strathclyde, Northern Ireland and South Glamorgan.
BT will initially run the trial with 50,000 end users and, "depending on the successful progress of the trial", aims to get 150,000 end users signed up.