The Turnbull government should split up the National Broadband Network and start preparing to sell it off to private companies, a landmark infrastructure plan says. 
The Infrastructure Australia report, which presents a 15-year vision for the nation's needs, says the NBN should be privatised in the "medium term".
"In the near term, the Australian government should commission a scoping study to assess the most appropriate approach, structure and timing to deliver a privatised NBN model," the report recommends.
"The scoping study to assess the most appropriate approach and structure for a privatised NBN should include options to efficiently support delivery of NBN services in regional and remote areas that are non-commercial."
The report adds: "It may be desirable to defer the privatisation of NBN Co until the rollout is complete, both to avoid disrupting a complicated infrastructure project and in recognition that private investors are likely to have less appetite for risk during the rollout phase."
The Turnbull government has instructed NBN to complete the national roll-out by 2020, four years later than it anticipated at the 2013 election.
The report also backs calls for the NBN to be broken up into separate units ahead of any sale.
"NBN Co should be split into distinct business units to encourage infrastructure competition, promote private investment, and allow for specialisation in managing different networks," the report says.
One option would be to separate the company based on technology.