Aurelius, a "distressed debt" fund, is asking investors to put the company into default as "a precautionary step," according to a Dec. 29 letter from the firm reviewed by Reuters. Under the terms of those bonds, Petrobras (PETR4.SA) is required to provide third-quarter financial statements within 90 days of the end of a quarter, in this case by Monday, Dec. 29. Petrobras has not published those accounts because allegations of contract-fixing and bribery at the company have raised doubts about the true value of its assets. For the default declaration to take effect on any of the more than 20 U.S. law bonds outstanding, investors holding at least 25 percent of any one series must request the action, Aurelius said in the letter to fellow bondholders. Aurelius was a leading member of a group of investors that refused to accept a debt restructuring with Argentina, taking the country to court.