A spokesperson for the Swiss bank was quoted by the newswire as saying that “this speculation is wrong”. The bank did not respond to this publication's request for comment at the time of going to press.

Some media reports recently suggested that firms such as Wells Fargo could buy this business. Wells Fargo’s chairman and CEO John Stumpf has said he would like to increase the firm’s share of the US wealth management sector, possibly by an acquisition.

UBS has suffered a run of problems in the US market including a damaging tax evasion case and huge credit losses. As reported recently, UBS Wealth Management in the Americas posted a pre-tax loss of SFr33million for the fourth quarter of last year, hit by litigation costs, but narrower than SFr47 million for the previous quarter. Inflows have improved, however.

Some analysts, such as at Morgan Stanley, have argued that UBS's prospects have improved, putting the worst of its recent troubles behind it.

In October 2009, Robert McCann, a former head of Merrill Lynch’s wealth management business, took over as CEO of UBS’s wealth arm. And earlier this year, the Zurich-listed firm's chief executive Oswald Grübel reiterated his optimistic forecast for the further growth and recovery of the US wealth management business.

But despite the changes, and improved client inflows and hires at the firm, speculation about UBS's Americas wealth business has not disappeared.