WASHINGTON The U.S. pulled back the veil on Switzerlands famed tradition of banking secrecy Wednesday, winning an agreement for banking giant UBS AG to disclose the names of 4,450 American clients suspected of hiding assets in Swiss accounts. The news is expected to prod thousands more UBS clients to voluntarily disclose their financial details to the Internal Revenue Service, lest they be pursued later.

The accounts held $18 billion at one time, though many have since been closed, said IRS Commissioner Doug Shulman. This agreement sends an unmistakable message to people hiding income and assets offshore, he said. The IRS will vigorously pursue tax cheats around the world, no matter how remote or secret the location.