Households and businesses across Scotland will be connected to high-speed broadband in a multimillion-pound plan described as one of the most ambitious in Europe.
Deputy First Minister Nicola Sturgeon announced the £264 million investment which aims to ensure 85% of properties have access to fibre broadband by the end of 2015.
The total should rise to 95% by the end of 2017, she said. Early priority will be given to rural small and medium-sized businesses to encourage economic growth in "hard-to-reach" areas. It builds on previous commitments across the Highlands and Islands.
Ms Sturgeon said: "Today's announcement signals the start of one of the most ambitious infrastructure projects in the whole of Europe. It will connect communities across rural and urban areas, providing a platform for future economic development and regeneration.
"Next generation broadband enables businesses to compete on the international stage. It has the potential to transform the way in which we educate our children, provide health and social care and deliver our public services. It provides Scotland with a platform upon which we can build and sustain a world-class digital country."
The project will be delivered by BT, which is investing £106.7 million, and is being led by the Scottish Government with councils and the UK Government's Department for Culture, Media and Sport.
Ms Sturgeon announced the plan at the BT exchange building in Pitt Street, Glasgow where the contract was signed.
Bill Murphy, BT managing director of Next Generation Access, said: "Having invested significantly in our own commercial project to build a fibre network covering almost 1.5 million premises in Scotland, we're incredibly excited to be working in partnership with the Scottish Government and local authorities to extend the technology into those mainly rural and remote parts of Scotland that the market alone could not reach."
David O'Neill, president of the Convention of Scottish Local Authorities, said: "Local communities, especially in rural areas, have been uniformly clear across Scotland that better accessibility to higher-speed broadband services was a top priority and for that reason all 32 Scottish councils agreed to pool over £90 million to deliver this project alongside European Union funding of over £20 million."
Ed Vaizey, the UK Communications Minister, said: "The complex and remote landscape of much of Scotland makes this one of the largest and most challenging projects in our nationwide roll-out of super-fast broadband."