UBS is expected to be hit with a $1 billion-plus fine to settle charges of rigging Libor interest rates this week.
This will make it the second bank to be brought to book for its role in the global scandal.
The fine, to be imposed by regulators in Britain and the US, would be the latest blow for the Swiss bank.
It has suffered a rogue trading scandal last year, paid a $780m fine to settle a US tax investigation in 2009 and nearly collapsed in 2008 under the weight of huge subprime losses.
Sources familiar with the matter have told Reuters the fine will be $1 billion or more, which would be more than double the $450m levied on British bank Barclays in June for interest rate manipulation.
The penalty could be as high as $1.6 billion and UBS will admit 36 traders around the globe manipulated yen Libor between 2005 and 2010, Swiss newspaper Tages-Anzeiger said, citing unnamed sources.
UBS declined to comment on the report or on the timing of a settlement.
While Barclays' settlement touched off a firestorm that forced its chairman and chief executive to quit, previous scandals at UBS have already prompted culls of top bosses as well a decision to wind down parts of the investment bank that have tarnished the bank's name.
Swiss commentators suggested the Libor affair would stiffen the resolve of UBS top management - all installed after the period under investigation - to focus on the core business of wealth management as they trim risky trading activities.
However, the settlement - which sources say is likely to come sometime this week - could add to global public and political anger about standards and culture across the industry.
