FACTBOX-U.S. indictments in UBS-related tax evasion probe

Aug 20 (Reuters) - The U.S. Justice Department on Thursday indicted a Swiss bank executive who once worked for UBS UBSN.VXUBS.N and a Zurich lawyer on charges they helped wealthy American clients evade U.S. taxes.

The whereabouts of Swiss banker Hansruedi Schumacher and lawyer Matthias Rickenbach were not immediately known. But their indictments brought to 10 the number of people charged in the United States so far in a sweeping tax evasion probe, centering largely on UBS, that dates back to 2007.

Now that the Swiss banking giant has agreed to disclose the details of 4,450 accounts of Americans suspected of concealing assets from U.S. authorities, the indictments are expected to mushroom. And they could extend high up into the ranks of the affluent.

-- Former UBS bank executive Bradley Birkenfeld and Mario Staggl, a banker who was not an employee of UBS, were indicted by federal prosecutors in Florida in April 2008 on charges they helped billionaire American property developer Igor Olenicoff evade taxes. Birkenfeld, an American, is due to be sentenced on Friday and Staggl, a citizen of Liechtenstein who has not appeared in court since his indictment, is a fugitive.

-- Olenicoff pleaded guilty to a single count of tax evasion in November 2007.

-- Raoul Weil, a Swiss citizen who was then head of wealth management at UBS, was charged in Florida in November 2008 with conspiring to help thousands of Americans hide $20 billion in assets from U.S. authorities. Weil, who reiterated his earlier claim of innocence in a statement issued by his U.S. attorney this week, has not appeared in court since his indictment and is a fugitive.

-- Three U.S. clients of UBS have been charged in south Florida since April with using accounts at the bank for tax evasion. All have pleaded guilty and a fourth customer of the bank was indicted in California last week. (Editing by Jim Loney, editing by Matthew Lewis)