By Megan Murphy and Patrick Jenkins in London

UBS is preparing to provide investors with details of a strategic plan that will shrink its investment bank?s balance sheet by half following the anointing of Sergio Ermotti as permanent group chief executive.

Mr Ermotti?s confirmation on Tuesday came just two months after he was vaulted into the role on an interim basis following the departure of Oswald Gr?bel in September in the wake of a $2.3bn unauthorised trading scandal.

Carsten Kengeter, the head of UBS?s investment bank, will stay on to oversee a sweeping restructuring of the Swiss group, according to people familiar with the matter, despite being passed over for the top job and still facing pressure to step down over the trading losses.

The reshuffle led some analysts to question whether UBS had rushed the chief executive search process in advance of a critical meeting with investors in New York on Thursday, where the bank will outline its strategy for shrinking its investment bank and shifting resources towards its core wealth management business.

The Swiss group is set to reveal at that meeting a target for group return on equity, a key measure of profitability, of between 13 and 14 per cent – a range well below previous levels, according to people familiar with the plans.

Aiming to reassure investors about the credibility of that strategy, UBS also on Tuesday moved up the timetable for the replacement of its chairman, Kaspar Villiger, in favour of Axel Weber, the former Bundesbank president.

?We don?t need the second coming of the Messiah,? said one UBS executive, in defence of Mr Ermotti?s rapid ascent. ?We need a safe pair of hands.?

Mr Kengeter, once the favoured internal candidate to succeed Mr Gr?bel, had been expected to leave shortly after the investors? meeting, having seen his chances at the top job crippled by the trading scandal.

According to people familiar with his thinking, however, Mr Kengeter is committed to seeing through the restructuring of the investment bank.

UBS has also not ruled out clawing back bonuses set aside for its investment bankers over the first nine months of the year.

? The Financial Times Limited 2011