By Luc Cohen

NEW YORK (Reuters) -Swiss private bank Banque Pictet has admitted to helping U.S. taxpayers hide more than $5.6 billion from the Internal Revenue Service (IRS) and has entered into a deferred prosecution agreement with the Justice Department, federal prosecutors said on Monday.

According to prosecutors, U.S. taxpayers with Pictet accounts in Switzerland and elsewhere evaded about $50.6 million in taxes between 2008 and 2014. As part of the agreement, Banque Pictet agreed to pay $122.9 million to the U.S. Treasury.

"This case should provide a clear message to others who try to hide their assets and income offshore," Jim Lee, the chief of the IRS' criminal investigation division, said in a statement.

As part of the agreement, Pictet, which oversees 632 billion Swiss francs ($724 billion) in client assets, will implement remedial measures and cooperate with the authorities' investigation. If it complies for three years, U.S. prosecutors will move to dismiss charges of conspiring to defraud the IRS.

"Pictet is pleased to have resolved this matter and will continue to take steps to ensure its clients meet their tax obligations," the bank said in a statement.

U.S. authorities have long accused Swiss banks of helping wealthy Americans evade taxes, and Pictet signalled it had been in contact with the U.S. for more than a decade.

Credit Suisse in 2014 agreed to pay a $2.5 billion fine for helping Americans evade taxes in a conspiracy that spanned decades. The bank has since been taken over by former rival UBS.

In 2016, two former Julius Baer bankers pleaded guilty to helping American clients dodge taxes, and the bank agreed to pay $547 million to resolve the criminal case.

Prosecutors said that while Pictet adopted some measures to ensure U.S. clients complied with the law, it helped some customers hide funds from the IRS in offshore accounts.

The bank's disgorgement of funds includes $52 million in fees that Pictet earned from the undeclared accounts, $32 million in unpaid taxes, and a $39 million penalty, prosecutors said.

The agreement comes as Renaud de Planta, senior partner at Pictet since 2019, prepares to step down from the helm to be succeeded by Marc Pictet from July 1.

($1 = 0.8732 Swiss francs)

(Reporting by Luc Cohen in New York; Additional reporting by Noele Illien in Zurich; Editing by Jan Harvey, Bill Berkrot and Christina Fincher)