Henry Seggerman entered the plea to conspiracy and other charges before a magistrate judge in U.S. District Court in Manhattan. Prosecutors said the charges stemmed from a scheme in which the Seggermans hid more than $12 million left by their father, Harry Seggerman, who died in May 2001 in Fairfield, Conn., at age 73.
The elder Seggerman, a vice chairman of Fidelity Investments before he retired in 1992, was one of the first mutual fund managers to invest in companies in Asia after World War II.
Henry Seggerman, at his plea hearing, confessed to evading Internal Revenue Service taxes from 2001 through 2010.
"I deeply regret my participation in these activities and intend to make amends for my conduct," said Seggerman, who lives in Manhattan and Los Angeles.
Seggerman pleaded guilty to conspiracy, subscribing to a false estate tax return and aiding and assisting the preparation of false tax returns for his brother.
His siblings Suzanne Seggerman, of Manhattan; Yvonne Seggerman, of Cumberland, R.I., and Edmund Seggerman, of Washington, D.C., had each previously pleaded guilty to conspiracy.
U.S. Attorney Preet Bharara said in a statement that the Seggerman siblings "inherited and continued a family tax fraud scheme.
Prosecutors said Harry Seggerman left an estate worth more than $24 million, with more than half of the money held in secret and undeclared foreign bank accounts. They said the more than $12 million in overseas accounts was left to his surviving spouse and five of his children.
According to the charges, Henry Seggerman signed a tax return for his father's estate that failed to report more than $5 million left to the businessman's wife and more than $7.5 million left to five of his children.
No sentencing date was set, in part because Seggerman signed a cooperation agreement that might earn him leniency. He and his siblings, all in their 50s or early 60s, each face up to 11 years in prison.