UBS Group AG, the largest Swiss bank, said its wealthiest clients will be attracted to US dollars after Switzerland roiled markets by scrapping the franc's cap.

Private-banking customers are concerned a stronger franc will hurt Switzerland's economy and the businesses they own, said Simon Smiles, Zurich-based chief investment officer for ultra－high-net-worth individuals at UBS.

Clients worldwide have yet to decide on whether to change currency allocations, he said. UBS cut its growth forecast for Switzerland and predicts the country will slip into deflation this year.

"We did six client group calls one after another as soon as the news came out. Broadly, the allocation toward dollars and people's preference toward US assets has increased over the last two to three quarters," he said.

"The uncertainty associated with this move in Switzerland will incrementally increase that preference for US assets."

The Swiss National Bank stunned markets on Thursday by abolishing the franc's three year-old cap of 1.20 per euro, causing the currency to soar as much as 41 percent against the common currency. The central bank also made its deposit rate more negative, underscoring Europe's divergence with the US, where the Federal Reserve is considering an increase in borrowing costs.

Asian shares dropped while bond yields in Japan and Australia fell to records on Friday as investors flocked to haven assets. Thirty-year US debt yields declined to an all-time low of 2.35 percent on Thursday.

"The US remains very much the safest and strongest story in terms of economic growth, corporate earnings and potentially US dollar appreciation," said Smiles, who advises clients who each have more than 50 million francs ($57 million) in investable assets at UBS.

The Bloomberg Dollar Spot Index, which tracks the US currency against 10 major peers, rose 11 percent last year, the most since the gauge's inception in Dec 31, 2004.

UBS lowered its forecast for Switzerland's economic growth in 2015 to 0.5 percent, from 1.8 percent.