The operation meets requirements of a financing deal between BNDES and Petrobras pipeline unit Transportadora Associada de Gás S.A. (TAG), according to a securities filing.
Petrobras said the funds came from the sale of offshore block BM-S-8 to Norwegian firm Statoil.
"This is an important step that utilizes cash from divestments to reduce our debt," the filing said.
Stricken by a corruption scandal and an oil price downturn, Petrobras is hoping to raise US$35bn from asset sales between 2015 and 2019.
The company's debt stood at US$123bn at the end of September. The figure is around three times greater than that of ExxonMobil, which reported a third-quarter profit of US$2.65bn compared to Petrobras' US$4.8bn net loss.