As UBS considers the future shape of its integrated banking model, the boss of Deutsche Bank’s wealth management division said that big banks do not need investment banking to succeed, Reuters reported.

"Investment banking is not a precondition to be a good wealth manager... But if you have one there are a lot of synergies," Pierre de Weck reportedly told a conference, citing the example of pure-play Swiss private bank Pictet.

De Weck, who joined Deutsche Bank in 2002 from UBS where he headed the global corporate and institutional division, commented in response to a question about UBS and its recently revealed $2.3 billion trading loss. UBS chief executive Oswald Grübel has resigned.

The affair has reignited debate on whether it is in the best interests of wealth management clients for their bank to be closely allied to an investment bank. Firms such as UBS, Citigroup, Credit Suisse and HSBC operate integrated banking models. On the other hand, firms such as Pictet and Julius Baer do not engage in investment banking, preferring a “pure-play” approach.

In the comments, Deutsche’s De Weck reportedly said 30 per cent of net new assets in Deutsche's wealth management division came from investment banking that accounts for about 60 per cent of the German bank.

But he said the private bank did not just take products straight from the investment banking arm.

"If you subordinate to the investment bank you cannot give independent advice," he said. "There are a lot of advantages but there are also some pitfalls and dangers."