BT has announced that it is to extend the availability of its next-generation ADSL broadband service to a further 2.5 million homes.
Around 900,000 of these are in rural areas and BT promises that many will see download speeds double.
The news comes as Ofcom reveals that the average speed of broadband in the UK is 6.8Mbps (megabits per second).
It criticised ISPs for continuing to use maximum speeds, unachievable by most customers, in their advertising.
BT had already pledged to roll out its faster ADSL technology to 80% of the UK and this latest announcement means it will now reach 90%.
The technology that it is using relies on the older copper wire telephone network, and offers speeds of up to 20Mbps.
However, few people will achieve the maximum speed because ADSL degrades the further a house is away from the exchange.
BT said that both fibre and its advanced copper broadband will "play a critical role" in increasing average broadband speeds around the UK.
"This is a significant expansion of our roll out plan and is further proof of our commitment to serve rural areas," said Alex Pannell, BT's director of product management.
The telco is also rolling out fibre services to two-thirds of the UK. It plans to complete this by 2015.
The government has promised to make the UK the fastest broadband nation in Europe by that date, following years of languishing in the middle of the speed league tables.