U.S. top court rejects ex-UBS trader's challenge to Libor indictment

The U.S. Supreme Court on Monday rejected a bid by a former trader with Swiss global financial services company UBS AG to dismiss a criminal indictment filed by U.S. prosecutors over his alleged role in Libor benchmark interest rate manipulation.

The court's decision not to hear the appeal brought by Swiss citizen Roger Darin means the 2012 charges will not be thrown out, leaving in place a March 2016 ruling by the New York-based 2nd U.S. Circuit Court of Appeals. Darin has remained in his home country, meaning he cannot be arrested. Darin has never appeared in U.S. court, and Switzerland does not extradite its citizens.

Libor, or the London interbank offered rate, is a short-term rate that underpins hundreds of trillions of dollars of financial products from mortgages to credit card loans.

According to the U.S. Justice Department, Darin was primarily focused on trading yen-dominated short-term interest rate derivative products. While at UBS, he worked in Singapore, Tokyo and Zurich.

The criminal complaint said Darin conspired with co-worker Tom Hayes to commit wire fraud by agreeing to submit yen Libor opinions to benefit Hayes' positions.

Hayes, who was prosecuted in Britain, is serving an 11-year prison sentence after being found guilty of conspiring to rig Libor benchmark interest rates.

In resolving a similar investigation into the rigging of currency markets, UBS reached a $1.5 billion settlement with U.S. authorities in 2012, and in May 2015 agreed to pay a $203 million criminal fine for breaching its own non-prosecution agreement.

(Reporting by Lawrence Hurley; Additional reporting by Nate Raymond; Editing by Will Dunham)