Under the scheme, more than 600,000 Scottish homes and businesses are already due to get access to superfast speeds; some £101m has been invested to date.
The Culture Department said the current rural programme would deliver returns of £20 for every £1 invested, giving "tremendous value for money".
As well as improvements in the productivity of broadband firms, it said faster broadband would create an additional 56,000 jobs in the UK by 2024, and the work involved in the current roll-out was expected to provide a £1.5 billion boost to local economies with approximately 35,000 "job-years" created or safeguarded over the period to 2016.
By 2024, the UK Government's investments in faster broadband are set to boost rural economies by £275m a month or around £9m a day.
The department also said more than 10,000 homes and businesses across the UK were now gaining access each week; this figure is expected to reach 40,000 per week by the summer.
Last night, a Scotland Office spokesman said: "Today's announcement from the UK Government of additional funding to support an extension of the rural broadband roll-out will ensure even more homes and businesses across Scotland have access to superfast fibre broadband."