Chief Executive Officer Sergio Ermotti said that the global slowdown and the difficulty making a profit in the face of new regulations prompted the layoffs.
The New York Times reported UBS lost $2.3 billion in the third quarter of the year, blaming much of that on its own restructuring plan and its own borrowing costs.
In the third quarter of 2011, the bank earned a profit of about $1 billion.
The bulk of the cuts announced Tuesday would be in its investment division, the bank said.
Overall, the firm plans to reduce personnel by about 16 percent, bringing its total workforce down to about 54,000.
"Some reductions will result from natural attrition and we will take whatever measures we can to mitigate the overall effect," Ermotti said.
With most of the job losses in the investment division, that implies a bulk of the job losses would occur in London, where its investment division is centered.
About 4,500 jobs in London are likely to vanish while 2,500 jobs in Switzerland are in peril, the Times said.