The 24.5km section completes the 90km-long international route No. 60 in Valparaíso region.
Prosecutors are investigating concessions in Paraná state, and one of the companies under the microscope is a subsidiary of Triunfo Participações e Investimentos.
Uncertainty is the only certainty in key elections in Latin America, according to the latest BNamericas Political Risk report.
A high-ranked government official said resources will be needed to cover debts and investment commitments of the Brazilian utilities over the coming years.