UBS employees in institutional equity sales and structured insurance products reportedly were among the first casualties of the latest round of layoffs that the biggest Swiss bank announced last week.

As many as 400 individuals from the two departments were fired last week, TheStreet.com reported Friday, citing unnamed sources at UBS's U.S. headquarters in Stamfort, Conn. The layoffs followed the bank's first-quarter release earlier in the week, featuring a $10.9 billion net loss, a $19.5 billion write-down and a plan to eliminate as many as 2,600 jobs from its troubled investment bank division and 5,500 jobs company-wide.

"Some insiders expressed surprised at the areas in which the cuts came," TheStreet.com said. Indeed, UBS's first-quarter losses stemmed from morgtage bonds (both residential and commercial), auction-rate securities, leveraged loans, and tumbling deal volume. Meanwhile, a handful of other areas including cash equities, prime brokerage and exchange-trade equity derivatives recorded increased business compared with a year earlier, as eFinancialCareers News reported May 7.