UBS, the biggest victim of the credit crunch in Europe, has hired Lazard, the financial advisory group, to conduct a review of the bank to help to decide which of its businesses should be expanded and which reduced.

UBS has lost more than $37 billion (£18.7 billion) in the past nine months, mostly in the form of investments relating to sub-prime mortgages, and is facing intense pressure to restructure its business. The wealth management division, although highly regarded, has seen its clients withdrawing cash on fears that the group will be weakened by its losses.

At the same time, Olivant, the activist investor that has a 2.5 per cent stake in UBS, has pressed the board to sell its asset management business.

However, the bank is expected to expand or reduce various business lines, rather than spin off or sell an entire unit, as a result of the review.

Lazard's appointment is thought to be connected to a long-running review of the bank being undertaken by Marcel Rohner, UBS's chief executive.

In recent months, UBS executives have said that they are keen to focus more heavily on client businesses, such as prime brokerage and mergers and acquisitions advisory work.

The group has also said it aims to spend less on so-called proprietary trading - investing from its own balance sheet.

Separately, UBS announced two small deals yesterday that may give an indication of where its business review is headed. It bought VermogensGroep, a private Dutch bank, to boost its wealth management division, for an undisclosed sum.

It also announced the sale of Fiduciary Trust, an investment management company, to Wilmington Trust. The unit, based in New Jersey, manages 800 retirement and benefit plans with a combined $5.5 billion of assets.

UBS appointed Marcel Rohner as chief executive last year and this year replaced Marcel Ospel, the chairman, with Peter Kurer.

In May the bank announced 5,500 job cuts, including 2,600 at its investment bank. Fewer than 900 jobs are expected to be lost from the investment bank in London, where UBS employs about 9,000 people.

Lazard and UBS declined to comment on the review. Shares in UBS rose 5 per cent to SwFr23.94.

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