"This sequence of events deprived Collins of his right to be present at every stage of the trial. Because the deprivation was not harmless, we vacate and remand for a new trial," the appeals court wrote.
The lawyer from Winnetka, Ill., was convicted in July 2009 of conspiracy and other charges. Federal sentencing guidelines had called for 85 years in prison.
Refco was once one of the nation's largest independent commodities brokers.
The company in the mid-1990s sustained hundreds of millions of dollars of losses through losing trades and engaged in an elaborate campaign to cover them up, attracting the attention of federal authorities. Refco filed for bankruptcy in 2005, just weeks after going public and soon after revealing that a $430 million debt owed to the company by a firm controlled by former Refco CEO Phillip Bennett had been concealed.
Before its fall, Refco employed some 2,400 employees in 14 countries. Bennett is serving 16 years in prison after pleading guilty to conspiracy to commit securities fraud.
A message for comment left with lawyers in the case wasn't immediately returned.