The former chief executive of US brokerage Refco has been charged with securities fraud, sending the company's shares down 22% in New York.
Refco is a commodities and futures brokerage
Phillip Bennett is accused of hiding millions of dollars of debt owed to Refco by another firm he controlled.
The purpose of such a move was to make Refco look stronger than it was ahead of its $583m (£333m) float in August, US Attorney Michael Garcia alleges.
Mr Bennett has been put on leave by Refco, where he was also chairman.
Mr Garcia said that "others known and unknown" were also involved in the alleged crime.
Mr Bennett first joined Refco in 1981 and was appointed chief executive in 1998.
He faces up to 20 years in prison if found guilty.
Refco is one of the world's largest commodities and futures brokerages.