Swiss banking giant “UBS” sacks its chief executive.

Swiss banking giant UBS has announced the surprise resignation of its chief executive Peter Wuffli following a turbulent period for the bank marked by difficulties in the US mortgage market.

Wuffli will be replaced by his deputy, Marcus Rohner, who has served as chairman and chief executive of the company's corporate banking and global wealth management arms, UBS said in a statement.

These businesses "have made the largest contribution to the firm's revenues and profit" over the last few years, making Rohner "well-prepared for his new role," the bank said.

Wuffli, 49, has presided over the costly closure of an in-house hedge fund, Dillon Read Capital Management (DRCM), which faltered badly in the US mortgage market.

UBS has also seen a disappointing spell of overall financial results under Wuffli's watch, with net profit falling by 7.0 percent in the first quarter of 2007 to 3.275 billion Swiss francs.

By contrast, a year earlier first quarter net profit rose 12.7 percent.

However, market players warned that UBS must do more to reassure the market of a coherent strategy and focus in the wake of Wuffli's departure.

UBS shares were up 0.5 percent at 74.15 Swiss francs in early morning trading (0817 GMT) on the Zurich stock exchange.