Calls for UBS to speed up the release of rogue trader report

Delaying results of investigation into $2.3bn losses could further damage bank's reputation

Pressure is growing on UBS to move quickly to publish the results of its investigation into how a rogue trader was able to run up a $2.3bn loss in its London investment banking division.

Carsten Kengeter, the head of UBS's investment banking arm, is understood to be close to finalising the review, which will to lead to big cuts to many of its London trading activities and significant job losses.

The Swiss bosses want the London arm, which has one of the biggest equity capital markets divisions, to carry less risk, shrink its balance sheet and concentrate on client-focused advisory businesses.

An announcement, due this week, may now be scheduled for the week after. But sources yesterday suggested that Mr Kengeter is being urged by his Swiss bosses to move more rapidly as they want to contain the damage to the bank's reputation which was still recovering from its near collapse during the 2008 financial crisis.

The latest scandal, in which a London-based trader, Kweku Adoboli, is alleged to have run up losses of $2.3bn, has already led to last month's resignation of UBS's chief executive, Oswald Gruebel. Mr Gruebel was brought out of retirement in 2009 to reform UBS after it nearly collapsed under the weight of more than $50bn of toxic US mortgage-backed securities.

Now the Swiss want the London bank to shrink many of its activities and refocus on core advisory, capital markets, client flow and solutions businesses. There is also a growing view among Switzerland's top bankers and politicians that the country cannot afford to have its two biggest banks – Credit Suisse and UBS – exposed to such volatile and high-risk trading activities and that it is UBS which should be cut back.

UBS's chairman, Kaspar Villiger, said last week that in the future the investment bank will be less complex, carry less risk and use less capital to produce reliable returns and "contribute more optimally to UBS's overall objectives." The Swiss directors are said to want a return to the old-style advisory business that UBS acquired in 1998 when it merged with Swiss Banking Corporation.

Several of UBS's big investors, including the Singapore Investment Group, have publicly expressed their concern over lapses at the bank. UBS is also preparing a full and more extensive review of the business to be presented to investors on 17 November.

UBS has also appointed headhunters Egon Zehnder to help search for a new chief executive to takeover from Mr Gruebel. The acting chief executive, Sergio Ermotti, is likely to be a strong internal candidate, while other potential names include the former JP Morgan boss Bill Winters.

Mr Adoboli has been charged with fraud and false accounting and has been remanded in custody until 20 October.