GLOBAL - Swiss bank UBS has decided to replace chief executive Peter Wuffli with his deputy Marcel Rohner, in a surprise move,effective today.

Standard & Poor's (S&P) said the decision did not affect the bank's AA+/Stable/A-1+ rating as the ratings agency quoted UBS as saying the move was not caused by "strategic disagreements".

Wuffli had been hand-picked by UBS chairman Marcel Ospel as his successor last year when he announced his retirement.

However, the board of directors decided against this nomination and asked Ospel to stay on "for at least another term of three years," UBS said in a statement.

The bank added the decision to "institute generational change in UBS's operational management" was made jointly by the board of directors and Wuffli.

Wuffli transfered all his functions in the bank to Rohner with immediate effect and left UBS.

In December 2001, Wuffli had been named CEO in a surprise re-shuffle of UBS' senior management following the dismissal of then-CEO Luqman Arnold. Wuffli was, at that time, CEO of UBS Asset Management.

Rohner's place as chairman and chief executive of Global Wealth Management & Business Banking will be taken by Raoul Weil, member of the Group Executive Board.

The bank stated "the board of directors is extremely grateful to Peter Wuffli for his substantial contribution to the growth of UBS, especially to the expansion of its franchise, market position and brand strength".

No spokesperson was available to comment to IPE before deadline.

S&P noted UBS was facing growing scrutiny following"ill-fated" losses in its Dillon Read Capital Management hedge-fund venture earlier this year and the ensuing shut-down of the in-house venture.

However, the ratings agency pointed out succession should run smoothly as Rohner "has performed well as head of UBS' market-leading wealth-management business".

Problematic issues UBS will have to tackle are the incorporation of Dillon Reid into the investment bank and the impact of several high-profile departures over the last months, an S&P spokeswoman suggested to IPE.