UPDATE 1-Ex-UBS banker to plead guilty, cooperate - WSJ

(Adds Justice Department no comment, efforts to reach lawyer, background)

NEW YORK, May 29 (Reuters) - A former UBS AG (UBSN.VX) private banker, facing prosecution for participating in a U.S. tax-evasion scheme, is scheduled to enter a guilty plea next month in federal court, according to a report Thursday in the online version of the Wall Street Journal.

Citing people familiar with the matter, the paper reported that the banker will aid a U.S. Justice Department probe aimed at the Swiss-based bank.

The paper reported Bradley Birkenfeld is expected to provide the Justice Department with the names of a number of wealthy Americans who used UBS to avoid paying taxes, people with knowledge of the investigation said.

UBS would not comment on the report. A Justice Department spokesman had no comment and Birkenfeld's lawyer could not be reached for comment.

According to an online court notice, Birkenfeld is scheduled to enter a changed plea at a June 9 hearing before U.S. District Judge William Zloch in Fort Lauderdale, Florida.

Birkenfeld had pleaded not guilty previously.

Earlier this month an indictment was unsealed charging Birkenfeld and Mario Staggl with conspiring to defraud the United States by helping an unidentified U.S. billionaire real estate developer hide $200 million in assets from tax authorities.

UBS has said the Justice Department and the Securities and Exchange Commission are investigating its conduct in relation to cross-border services provided by UBS advisers to U.S. clients from 2000 to 2007. (Reporting by Ed Tobin, Jim Vicini and Gina Keating; writing by Tim Dobbyn, editing by Leslie Gevirtz)