The Lava Jato task force apprehended 19 suspects in the Brazilian state over alleged bribe payments, among them the road concessions association's CEO.
The infrastructure sector, however, still doesn't show signs of recovery.
Three companies obtained loans from the Brazilian development bank.
The government wants to guarantee shipping conditions on the river throughout next year, after noticing that the planned US$766mn PPP for the river had a six-month period that did not include dredging works.
Debenture issues to finance infrastructure projects hit a record high in the first seven months.