ACS, which currently owns 46.3% of the toll highway, is slated to close the deal before the end of this year, the report said.
The remaining shares of the tollroad belong to German firm Hochtief, of which ACS is a majority shareholder, as well as Spanish firm Cofides.
The 30km Vespucio Norte, part of Santiago's beltway, runs from Huechuraba to Maipú, and was awarded to ACS in 2002 under a 30-year contract by the public works ministry (MOP) for US$320mn.
The sale could exceed the original concession price, according to the report.
ACS will use the proceeds from the sale to compete for other Chilean concessions. The company is already prequalified for the upcoming Vespucio Oriente concession through its subsidiary Iridium.
Brookfield Infrastructure Partners was established by Brookfield Asset Management (TSX: BAM.A, NYSE: BAM) as its primary vehicle to own and operate infrastructure assets.