According to the results of the survey, which looked at the situation in over 70 countries, many private banks are counting on annual growth of between 5% and 10% over the coming years. However, speaking to the Swissinfo news service, PwC private banking expert, Bruce Weatherill suggested that they are unlikely to get it.

With specific regard to the Swiss situation, Mr Weatherill cited problems with maintaining acceptable levels of banking secrecy in the face of international pressure.

"That's not to say there won't be a Swiss compromise," he observed, adding that:

"What's clear from the survey is that banks need to meet the base criteria for regulation internationally. If one doesn't meet those, it'll be very dangerous for the banks. The indication is that Switzerland wants to play in the international marketplace - so they'll make themselves compliant."

According to recent reports, the Swiss private banking industry has responded to the relatively slim pickings in the upper end of the wealth spectrum by increasing efficiency - streamlining, cutting staff numbers and costs, and focusing on key markets.

In some cases, Swissinfo revealed, the belt-tightening has already worked to good effect, with several banks recently reporting healthy profits.