THE Scottish Government has published more details about its forthcoming invitation to companies to tender for next generation broadband roll-out, due to start in September.

The contracts for the transformative project to achieve 80-90% "superfast" coverage are expected be awarded in April 2013.

According to the document Step Change 2015 the work will be appointed under the UK-wide Broadband Delivery Framework, rather than a Scotland-only "competitive dialogue" after a review "concluded that [this] would be a faster means of achieving our ambitions".

However The Scottish Government has accused the Department of Culture Media and Sport of "dragging its feet" on the formulation of the framework.

Scottish Government total cost estimates for the upgrading of Scottish network, largely through the use of fibre broadband, range from £550 million to £750m, with public sector intervention in the range of £190m to £350m.

The document adds that "the level of uncertainty around costing is not unusual at this stage of a major infrastructure project."

Yesterday's procurement plan follows a strategy document on "world-class digital infrastructure for Scotland by 2020" unveiled in January by Cabinet Secretary for Infrastructure Alex Neil outlining steps towards "pushing Scotland to the forefront of the digital revolution."

The Scottish Government has already identified about £250m of public sector funding, including around £40m earmarked by local authorities. Additional funds are expected to be confirmed from BDUK, which has so far committed £68m, and other local authorities.

Mr Neil said "Faster internet access- will ensure our communities, particularly those in rural and remote areas, remain vibrant, strong and connected. The procurement plan, backed by our major investment for faster internet connections will boost economic growth and connect communities wherever they are in Scotland.

"Research has shown that next generation broadband investment could boost a town's economy by about £143m."

The Scottish Government has lobbied for an increased allocation from BDUK, saying the initial allocation did not take sufficient account of "challenges of delivering digital infrastructure to remote and rural communities."