The costs switched the Swiss bank's third-quarter results into a 2.2-billion Swiss franc net loss compared to the 1.0 billion net profit it had reported during the July-September period last year.
"This decision has been a difficult one, particularly in a business such as ours that is all about its people," UBS chief executive Sergio Ermotti said in a statement, referring to the job cuts.
"Some reductions will result from natural attrition and we will take whatever measures we can to mitigate the overall effect," he said, vowing that "our people will be supported and treated with care."
The Zurich-based bank said that cuts in its overall staff numbers to about 54,000 by 2015 was a necessary part of a restructuring of its investment bank, including shedding some of its high-risk activities and basically withdrawing from the fixed income business which had burdened it with catastrophic losses during the 2008 "subprime" crisis.
UBS, which counted nearly 64,000 employees at the end of September, said the restructuring would save 5.4 billion Swiss francs (4.5 billion euros, $5.8 billion) over the next three years.
UBS said in its earning statement it had taken a one-time charge of 3.1 billion Swiss francs linked to the restructuring and a debt-related charge of 863 million.