UBS interim chief executive Sergio Ermotti has ruled out the sale or spinoff of the Swiss firm’s investment banking arm, reiterating previous statements that this business division will be shrunk, according to the Wall Street Journal.

Ermotti, appointed in September after CEO Oswald Grübel resigned in the wake of a $2.3 billion rogue trader loss, has previously said the firm intends to reduce the risk exposure of the investment bank. As a result, UBS will be increasingly concentrating on wealth management, seen as the flagship business line of the firm.

UBS announced in August it will shed 3,500 jobs, almost half of them from its investment bank, to cut around SFr2 billion from annual costs by the end of 2013. It was noted that the unauthorised trading loss of $2.3 billion that had been uncovered in London would largely cancel out that cost saving.

In a conference call in September when Ermotti’s appointment was announced, he said more details of the investment bank’s structure would be announced in November.

The trading loss has reignited debate on whether wealth management is best served by being a standalone business or whether it should have close links to an investment banking operation.