In a securities filing, Petrobras Distribuidora SA, as the country's top fuel distributor is formally known, said that it was found at fault alongside competitors Raizen and Air BP, for anticompetitive practices at Sao Paulo's Guarulhos airport, Brazil's busiest.
Cade's opinion has no immediate legal effect, but the body will present its findings in court, which could lead to significant fines. The nature of the allegations was not immediately clear, but Cade has previously said it was investigating whether those companies were acting to bar competitors' entry into the aviation gasoline market at Guarulhos.
In the Friday filing, BR Distribuidora said its business model was "based on the best commercial and competitive practices," adding that it would "adopt all means necessary for its defense."
Raizen, a joint venture between Royal Dutch Shell PLC and Brazil's Cosan SA, did not immediately respond to a request for comment, nor did BP PLC, the parent of Air BP.
(Reporting by Gram Slattery; Editing by Chizu Nomiyama)