This will take more than a Swiss Army knife.

Sergio Ermotti, the head of Swiss banking giant UBS, is picking up the ax and slashing 10,000 jobs, or 15 percent of the work force — a far more severe headcount reduction than Wall Street was expecting.

The cuts will fall heavily on fixed-income trading, where UBS must deploy a lot of its own capital to support traditionally riskier trading activity.

The bank’s coveted wealth management business will remain relatively unscathed, sources said.

A spokeswoman for UBS declined to comment.

Sources familiar with the plans say that the layoffs will be felt around the globe but will center on the investment banking unit.

Also, the pink slips will come in waves rather than one fell swoop.

Sources say the cuts will lead to a reduced role for investment bank co-head Carsten Kengeter, who in the past has clashed with co-head Andrea Orcel.

It’s unclear how many of the cuts will affect the New York metro area, where UBS has a big office in Midtown and another complex in Stamford, Conn. UBS has 63,200 employees globally.

Ermotti, who took over for former CEO Oswald Gruebel in the wake of a massive $2 billion trading scandal, has vowed to restructure the bank after it stumbled badly in the financial crisis.

Ermotti is hoping that the cuts, expected to be announced when the bank reports earnings on Tuesday, will help boost profits and improve the health of the bank’s balance sheet.

The Swiss bank’s retrenchment comes as the banking industry is facing tougher regulations and stricter capital requirements here and abroad.