Broadband ADSL speeds of up to 8Mbits/sec will be available for 99.6 per cent of British homes from March 31, BT announced today.

Software upgrades to equipment at more than 5,300 exchanges will enable BT, and the many providers who resell services, to offer the new BT ADSL Max and BT ADSL Max Premium links.

The services should be available more or less immediately to new customers but, depending on the service provider, it make take some months to upgrade existing users.

Speeds drop off rapidly with distance, so only people living very close to an exchange will get 8Mbits/sec, but BT reckons 78 per cent should get at least 4Mbits/second and 42 per cent at least 6Mbits/sec.

BT Wholesale said other newly-deployed technology should also make the service more reliable.

The upgrades are not the same as ADSL2+, which could offer up to 20Mbits/sec and is being installed by BT rivals at some exchanges.

Cable giant NTL is also trialling a 100Mbits/sec broadband service.