The work is budgeted at some US$21mn and involves the last 1.5km stretch of La Sirena avenue, which is expected to be finished by the second half of 2019.
The governor said the region "must be seen as the entrance and exit point of Chile."
The engineering and construction division of the conglomerate is looking more to the private sector for future expansion.
The US$54mn project entails expanding Punta Arenas airport's parking areas, passenger terminal and administrative building, among others.
Almost half will be in infrastructure, according to the bank.