Description:It's been a tough few years for UBS - rocked by a rogue trading scandal, a U.S. tax investigation and huge subprime losses. Now the Swiss bank is expected to be stung in the next few days by a $1.5 billion fine to settle charges of rigging Libor interest rates. It will be the second bank to pay a penalty to U.S. and UK regulators. The expected size of the fine has surprised some analysts.(2:10)