Companies bidding for the $310m are Sacyr Concesiones Chile, Intervial Chile and the consortium comprising Besalco-Icafal-Belfi.
Under a 40-year concession, works for the project involve the upgrade and expansion of 122km of Route 25, which connects Carmen Alto with Calama.
It also includes the East Ring Road in Calama, which will connect with Routes 24, 21, 23 and Route 25 all in the Region of Antofagasta. The government expects to complete works by 2024.
Economic proposals are now due by November 16.
Meanwhile, the Chilean senate has approved the plan to develop a Concessions Unit (Dirección General de Concesiones).
Alberto Undurraga, Minister of Public Works, said: "This will be a way to provide the government with more tools to develop public-private partnership faster and with a better control.”
The initiative will now be discussed in the third legislative process after being approved in the Chamber of Deputies, as well as in the commissions of Public Works and Treasury of the Upper House.