UK incumbent BT said Friday that it is to more than double the availability of its fastest fibre broadband service, delivering speeds of up to 100Mbps to around 2.5 million UK homes and businesses.

BT had originally planned to roll out FTTP (fibre to the premises) to approximately one million buildings as part of its overall plan to reach around ten million homes with fibre by 2012. The remaining homes would be able to receive fibre-to-the-cabinet (FTTC) services, delivering initial speeds of up to 40Mbps. But the carrier said it will now rollout FTTP as an upgrade in some areas rather than deploying the technology in new build sites only.

In the future, this infrastructure could be upgraded to deliver speeds of up to 1Gbps, BT said. Progress is already underway and the carrier claims 1.5 million homes will have access by next summer.

In June, the UK government published its Digital Britain white paper, setting out the importance of the digital economy to Britain’s economic future. The report outlines the steps that need to be taken by the UK to strengthen and modernise the country’s digital infrastructure to allow it to better compete in the global market.

The key points include the creation of equal access to at least 2Mbps broadband nationwide by 2012 through the creation of an investment fund; a £0.50 per month levy on all copper lines, which will go into the independent Next Generation Fund and will be available as a subsidy to operators willing to extend broadband coverage to the final third of homes where it is not available; the upgrade of all radio services to digital by 2015; changes to 3G licence terms, making them indefinite, rather than fixed term licences, which should encourage investment and deliver in building speeds of 1Mbps by 2013; and new powers for industry regulator Ofcom as well as a new requirement that the watchdog carry out a full assessment of the UK’s communications infrastructure every two years.