Switzerland's biggest bank, UBS AG, has reported a fourth-quarter net loss of 1.9 billion francs ($A2 billion) due to lawsuits and restructuring in the wake of a series of scandals.
That compares with a net profit of 324 million francs in the fourth quarter of 2011.
The bank was hit by a $US2-billion rogue trading scandal.
The Zurich-based bank attributed the fourth-quarter loss mainly to "net charges for provisions for litigation, regulatory and similar matters as well as net restructuring charges and an own credit loss".
UBS says it ended 2012 with a loss on the year of more than 2.2 billion francs, compared with a profit of 4.4 billion francs for 2011.
The bank reported its results before markets opened in Zurich on Tuesday.