The former chief financial officer of Refco Inc., one of the world’s biggest commodities brokerages, was accused in an indictment Tuesday of defrauding investors in a scheme that resulted in losses of more than $1 billion.

An indictment in U.S. District Court in New York charged Robert C. Trosten with conspiracy, securities fraud, false filings and wire fraud. It also added new charges to the case against Refco’s former chief executive officer, Phillip R. Bennett.