UBS cut 5,500 jobs and sold $15 billion (£7.6 billion) worth of damaged assets yesterday, but shares in Switzerland’s biggest bank fell by more than 4 per cent amid fears that restructuring would wreak further havoc.

The bank added to investors’ woes by revealing that rich clients were deserting its wealth management business and business banking clients in its home market had pulled almost SwFr2 billion (£960 million) from their accounts in the first quarter.

The job cuts will include 2,600 staff from UBS’s investment bank, which ran up most of the group’s $37.4 billion in credit crunch writedowns. Fewer than 900 jobs are expected to be lost from the investment bank in London, where UBS employs about 9,000 people. Marcel Rohner, the chief executive indicated that the worst of the staff cull was over.

UBS said that it had agreed to sell a $15 billion book of sub-prime mortgages to BlackRock, the asset management group. The mortgages had already slumped in value from $22 billion, the bank said.

UBS reported a SwFr11.5 billion first-quarter loss, SwFr500 million better than feared. As previously announced, there were $19 billion in writedowns in the three months to March 31. Shares in UBS closed down SwFr1.60 at SwFr35.28 each.

Meanwhile, a senior UBS employee, said to be Martin Liechti, the Zurich-based head of North and South America for its international wealth management business, was briefly detained in Miami last month by US authorities investigating whether the bank had helped American clients to evade tax. UBS said he has remained in the US.

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