Tai Nguyen, president of Insight Research LLC, admitted to participating in an insider-trading scheme that involved hedge fund Galleon Group LLC.

Nguyen, 49, pleaded guilty today before U.S. District Judge Naomi Reice Buchwald in federal court in Manhattan to one count of conspiracy to commit securities and wire fraud.

He was charged earlier today as part of a sweeping probe of illegal trading by Galleon. Nguyen’s name emerged last year in telephone records submitted by prosecutors in a criminal case against Donald Longueuil, a former portfolio manager at SAC Capital Advisors LP, who pleaded guilty to insider-trading charges.

Nguyen admitted to participating in a scheme that ran between 2006 to 2009. The charge carries a term of as long as five years in prison. Buchwald said that U.S. sentencing guidelines indicate he faces a range of 46 to 57 months.

Longueuil was sentenced in July to 2 1/2 years in prison.

To contact the reporter on this story: Patricia Hurtado in New York at pathurtado@bloomberg.net

To contact the editor responsible for this story: Michael Hytha at mhytha@bloomberg.net