Top U.S. Department of Justice lawyers defended the non-prosecution agreement with UBS AG and the guilty plea of a Japanese subsidiary, calling the $1.5 billion global deal with the bank a “very robust, very real and very appropriate resolution.”

Prosecutors announced on Dec. 19 that the Japanese subsidiary of UBS was charged with felony wire fraud for its role in the long-running manipulation of a leading interest rate benchmark, the London Interbank Offered Rate, or LIBOR.