Peter Schaer is believed to have been with UBS for 24 years and it is as yet unknown which firm he will be joining following his resignation from the Swiss banking giant.

Replacing Mr Schaer as executive director and head of the Dubai office is Juergen Wegner, who has been promoted to the role internally. His appointment is effective from today.

In other recent developments concerning the firm, Oswald Gruebel, UBS’s group chief executive, yesterday sought to reassure employees that the bank’s US wealth management operation is not for sale.

Mr Gruebel reportedly told staff in a memo that the bank had received offers for the business but had not taken any of them seriously.

Earlier this week Mr Gruebel was quoted in media reports as having called the US wealth management operation “non-core” - sparking fears of an imminent sell-off. Staff were told however that the term non-core is not a quality assessment and should merely be taken to mean a separate business which is not substantially integrated with the rest of the group.

Earlier this month unconfirmed reports emerged that between 150 and 200 jobs may be cut at UBS’s US wealth management unit. The firm is currently believed to employ 7,939 advisors in the US.