The South Australian government will spend more than $4 million in the next week's state budget to offer Adelaide businesses internet speeds up to 10 times faster than the National Broadband Network.

The project will use an existing fibre optic network jointly owned by the state government and the state's universities to roll out internet connections at selected locations offering speeds of up to 10 gigabits per second.

Premier Jay Weatherill says having access to ultra-fast internet will drive significant economic development and job creation opportunities and will embed South Australia as a leading centre for innovation.