Wegelin & Co., Switzerland’s oldest private bank, pleaded guilty to helping U.S. taxpayers hide assets from the Internal Revenue Service and may pay U.S. authorities as much as $74 million.

Otto Bruderer, a managing partner at the St. Gallen-based bank, entered the plea today to one count of conspiracy in Manhattan federal court. Wegelin in February became the first Swiss lender indicted in a crackdown on offshore firms suspected of helping Americans evade taxes.

“From about 2002 through about 2010, Wegelin agreed with certain U.S. taxpayers to evade the U.S. tax obligations of these U.S. taxpayer clients, who filed false tax returns with the IRS,” Bruderer, reading from a statement, told U.S. District Judge Jed S. Rakoff.

Under a proposed plea agreement, the bank will pay $20 million in restitution to the U.S., forfeit $15.8 million that represents fees on undeclared accounts and pay a fine of more than $22 million. The agreement requires Rakoff’s approval. Sentencing is set for March 4.

Taken together with the $16.2 million Wegelin forfeited from a U.S. correspondent bank account in April, the government would receive a total of about $74 million, Manhattan U.S. Attorney Preet Bharara said today in a statement.

‘Symbolic Significance’

“It has an important symbolic significance in that you have a bank that has no branches in the United States, but the U.S. government was able to reach them and get them to plead guilty,” said Robert Fink, a tax attorney at Kostelanetz & Fink LLP in New York. “It puts other banks on notice as to the long arm of the U.S. law.”

Prosecutors said that more than 100 U.S. taxpayers conspired with Wegelin and with Swiss bankers Michael Berlinka, Urs Frei and Roger Keller to hide income from the IRS. The individual defendants, who live outside the U.S., were first indicted in January 2012 and haven’t appeared in court to answer the charges. The bank held more than $1.2 billion in assets not declared to the IRS, according to the indictment.

Ex-UBS Clients

The U.S. said Wegelin and the three bankers wooed U.S. clients fleeing UBS AG, the largest Swiss bank. UBS avoided U.S. prosecution in 2009 by admitting it aided tax evasion, paying $780 million and handing over data on 250 accounts. It later disclosed information on about 4,450 more accounts.