The trustee seeking to recover money for Bernard Madoff's victims sued multi-billion dollar money-management firm Tremont Group Holdings Inc and sought an additional $555 million in recoveries from UBS AG .

Irving Picard, appointed by a U.S. bankruptcy court to liquidate Bernard L. Madoff Investment Securities LLC (BLMIS), said Oppenheimer Acquisition Corp, which bought Tremont Group in 2001, and Oppenheimer's parent corporations MassMutual Holding LLC and Massachusetts Mutual Life Insurance Co were also named as defendants in the lawsuit.

The lawsuit, which also names Tremont Group's founder and former Chief Executive Sandra Manzke and its former president and CEO Robert Schulman was filed under seal late on Tuesday in a Manhattan bankruptcy court.

Picard, in a statement, accused Tremont of being the second-largest feeder-fund network in the Madoff ponzi scheme, accusing it of ignoring obvious warning signs of fraud to maximize its own profits and self-interest.

The trustee, however, did not say how much money he sought to recover from Tremont.

Tremont was not immediately available for comment.

Picard also filed an additional complaint seeking to recover more money from UBS.

On November 24, the trustee sued UBS and others for more than $2 billion, accusing them of collaborating in the imprisoned swindler's ponzi scheme.

The second filing against UBS brings total recoveries sought from the Swiss bank to $2.5 billion.

UBS was accused of sponsoring foreign feeder funds that sent client money to the once-respected money manager, lending them an aura of legitimacy while shielding itself from liability through secret side agreements.

The trustee had earlier sued JPMorgan Chase & Co to recover $6.4 billion and HSBC for $9 billion.

Madoff is serving a 150-year prison sentence after pleading guilty in March 2009 to running a decades-long investment fraud of up to $65 billion, an unprecedented scheme that shook investor confidence in market regulators.

The Tremont lawsuit is In re: Picard vs Tremont Group Holdings et al, U.S. Bankruptcy court, Southern District of New York, No.10-05310. The UBS case is Picard v. UBS AG et al, U.S. Bankruptcy Court, Southern District of New York, No. 10-05311.

(Reporting by Sakthi Prasad and Santosh Nadgir in Bangalore; Editing by Unnikrishnan Nair)