Peter Madoff will serve 10 years in prison for his role in his older brother's multibillion-dollar Ponzi scheme, a U.S. judge said Thursday.

Peter Madoff, 67, pleaded guilty in June to criminal charges including conspiracy to commit securities fraud for falsifying the books and records of the investment advisory company founded by his brother, Bernard Madoff.

He agreed at the time not to oppose a request by prosecutors for a maximum 10-year prison sentence and agreed to an order requiring him to forfeit a symbolic $143.1 billion. U.S. District Court Judge Laura Taylor Swain approved the sentence on Thursday.

"I am deeply ashamed of my conduct," Madoff said at the sentencing. "I accept full responsibility for my actions."

Of 13 individuals charged criminally in connection with the fraud, Peter Madoff is the only one, other than his brother, who was a member of the Madoff family. Bernard Madoff, 74, was sentenced in 2009 to a 150-year prison term and was ordered to forfeit $170.8 billion.

(Reporting by Nate Raymond and Nick Brown; Editing by Eddie Evans)