Every telephone exchange in Wales is to receive a fibre upgrade by 2016, it has been announced.
The Welsh Government and BT have confirmed that deployment work will begin in each exchange area by September 2015 at the latest.
Hundreds more towns and villages are to gain access to super-fast broadband, allowing homes and businesses to improve their connectivity if they so choose.
Some 230,000 premises already have access to fibre broadband, with network upgrades already underway in every local authority area in Wales.
Julie James, Deputy Minister for Skills and Technology in the Welsh Government, said the Superfast Cymru programme is "ambitious and challenging".
She noted that the initiative will deliver fibre broadband across Wales, from Aberdaron in Gwynedd to Skenfrith in Monmouthshire.
"This is a tremendous achievement and excellent news for businesses and households," Ms James claimed.
She added that, by the time the Superfast Cymru programme is completed in spring 2016, Wales will be "one of the most highly connected countries in Europe".
Some 96 per cent of premises nationwide will be able to access faster internet speeds.
Ann Beynon, BT Director for Wales, said the latest announcement is "big news for the country", as people will know when work will start for every single telephone exchange.
She said the broadband provider is embarking on the biggest engineering programme seen in Wales over the last ten years.
It has the potential to improve the lives of individuals, families and businesses across Wales, Ms Beynon stated.
“Through BT’s own commercial roll-out, and now with Superfast Cymru, we are taking world-class speeds the length and breadth of Wales," she added.
“I’m particularly proud of our engineers who are working incredibly hard in often very rural and challenging areas to bring the benefits of super-fast broadband to Wales."