Swiss UBS bank in historic disclosure of accounts

The Swiss banking giant UBS is to disclose for the first time the identities of about 4,450 of its American clients suspected of using secret accounts to evade taxation.

The potentially historic disclosure could expose information about as much as $18 billion held at one point in clandestine accounts.

The Commissioner of the Internal Revenue Service (IRS), Doug Shulman, told reporters Wednesday morning that the names are what America's tax authority has really wanted all along.

"This is an unprecedented amount of information on taxpayers who've evaded their tax obligations," Shulman said.

Under US law, citizens must provide the IRS with information on amounts over USD 10,000 held in offshore bank accounts.

The Union Bank of Switzerland's move provides a resolution to the six-month legal tussle that put unprecedented pressure on Swiss banking secrecy.

In February, the Department of Justice (DoJ) on behalf of the IRS filed a lawsuit against the Zurich-based bank demanding information on as many as 52,000 American clients.

Under Swiss law, the affected depositors would have the opportunity to contest the release of their names and account information. Under an interpretation of US law, they might be required to disclose such appeals to the Justice Department, rendering moot any attempt to remain anonymous.