Of note, Petrobras has already delayed reporting its financial results twice so it can better assess the impact of a federal investigation into bribes the firm allegedly received from several major construction companies. Aurelius, a well-known legal vulture hedge fund, has fought countries such as Argentina and companies such as General Motors in U.S. courts, is trying to encourage holders of at least 25% of a series of Petrobras notes, the threshold needed for the default notice to be valid, to file for default.