The Justice Department indicted a Swiss private banking executive and a Swiss lawyer on Thursday, accusing them of selling tax evasion services to wealthy clients. The move opens a new front in Washington&S217;s challenge to Switzerland&S217;s tradition of bank secrecy.

The indictment, filed in United States District Court in Fort Lauderdale, Fla., charged Hansruedi Schumacher, a director at NZB Neue Z&>52;rcher Bank of Zurich, and Matthias Rickenbach, a Swiss lawyer, with one count each of conspiring to defraud the United states.

It came a day after the giant Swiss bank UBS said that it had agreed to disclose 4,450 American client names and account details, and it indicates that the American authorities are starting to pursue smaller players that may have helped Americans hide their money.

Mr. Schumacher is a former top private banker for UBS who left around 2002 to establish and oversee NZB&S217;s private banking operations. He worked at NZB until at least last month, the charges said. Mr. Rickenbach is a partner of the Rickenbach &&8; Partner law firm, with offices in Zurich and Geneva.

A Justice Department statement said that the two men &S220;helped their clients obtain offshore credit cards and created sham loan documents.&S221; It added that they &S220;falsified bank documents to generate the appearance that assets of their U.S. clients belonged to Swiss citizens, and they falsified documents to disguise their United States clients&S217; repatriation of offshore funds as inheritances from foreign citizens.&S221;

The statement said that &S220;the defendants told their clients that their assets and identification would be safer at NZB because they had no presence in the United States&S221; and were therefore &S220;less likely to be pressured by the American authorities to disclose the identities of their United States clients.&S221;

NZB is the unnamed &S220;Swiss bank&S221; mentioned in charges filed last month against an American client of the Swiss banking giant UBS, Jeffrey Chernick, claiming tax evasion on $8 million in assets. The indictments are a sign that American authorities are widening their attack on Swiss banking secrecy. Switzerland is the world&S217;s largest repository of hidden wealth, estimated to hold nearly one-third of the $7 trillion in assets believed to be held offshore.

The indictment also charged the two men with helping a second American, John McCarthy, a UBS client, to evade taxes, in part through offshore entities in Hong Kong linked to his UBS account.

Around 2007, the complaint says, Mr. Rickenbach&S217;s father hand-carried $5,000 to New York to deliver to an unidentified client.

NZB was established in 2000 by former senior executives from Bank Julius Baer, a prominent Swiss private bank. Over 2007 and 2008, Sarasin Group, another Swiss private bank, acquired a 40 percent stake in NZB, while NZB employees own the rest.

Thursday&S217;s indictment said that Mr. Schumacher &<51; who was referred to but not identified by name in the Chernick papers &<51; was a former manager of UBS&S217;s cross-border private banking division, the unit under scrutiny for having facilitated tax evasion by Americans.

Mr. Schumacher left UBS around 2002 to join NZB and help clients of UBS and other firms to evade taxes, according to the charges against him.

The new indictment said that Mr. Schumacher and Mr. Rickenbach paid $45,000 to a &S220;high-ranking Swiss government official&S221; in 2008 to learn whether Mr. Chernick was on a list of 285 names to be disclosed to American authorities in February as part of a broad settlement with UBS. Mr. Chernick reimbursed the $45,000 fee. The payment was referred to in the Chernick filing.

Mr. Schumacher, according to the Chernick filing, told Mr. Chernick that because the smaller bank had not entered into a special program with the Internal Revenue Service, it would be subject to less scrutiny by United States tax officials than UBS.

NZB&S217;s executives include senior names in the private banking industry. Martin Eberhard, the chief executive, was previously a senior executive at Julius Baer in charge of Swiss brokerage operations; Marco Bacchetta, the head of institutional sales, was previously in charge of the brokerage team at Pictet &&8; Cie Bank in Zurich, another well-known private bank.

Frank Gut, the chief financial officer, previously oversaw the Swiss Brokerage operations at Bank Julius Baer in Zurich. NZB&S217;s Web sitedescribes the bank as &S220;a financial institution which focuses on the brokerage business with institutional investors from Switzerland and abroad, and on asset management and investment advisory services for private clients.&S221;

The Justice Department established a special prosecutors&S217; team in 2007 that is focused on Swiss banks that help American clients evade taxes, according to a person briefed on the matter. During the UBS settlement, Douglas Shulman, the commissioner of the Internal Revenue Service, disclosed that the agency was looking at the activities of other banks and intermediaries in Switzerland.

U.S. Indicts Swiss Banker and Lawyer on Tax Charges