GENEVA (AP) Shares of Credit Suisse plunged 63% in early trading Monday after the announcement that banking giant UBS would buy its troubled rival for almost $3.25 billion in a deal orchestrated by regulators to stave off further market-shaking turmoil in the global banking system.

UBS shares were down 14% in early trading on the Swiss stock exchange.

Swiss authorities urged UBS to take over its smaller rival after a plan for Credit Suisse to borrow up to 50 billion francs ($54 billion) failed to reassure investors and the banks customers. Shares of Credit Suisse and other banks plunged after the failure of two banks in the U.S. raised questions about other potentially shaky global financial institutions.

Credit Suisse is among 30 financial institutions known as globally systemically important banks, and authorities worried about the fallout if it were to fail.

The deal was one of great breadth for the stability of international finance, Swiss President Alain Berset said as he announced it Sunday night. An uncontrolled collapse of Credit Suisse would lead to incalculable consequences for the country and the international financial system.

Switzerlands executive branch, a seven-member governing body that includes Berset, passed an emergency ordinance allowing the merger to go through without shareholder approval.

Markets remain jittery despite the best efforts of regulators to restore calm. Global stock markets sank Monday, with Hong Kongs main index sliding more than 3%. Market benchmarks in Frankfurt and Paris opened down more than 1%. Shanghai, Tokyo and Sydney also declined. Wall Street futures were off 1%. Oil prices plunged more than $2 per barrel.

Credit Suisse Chairman Axel Lehmann called the sale to UBS a clear turning point.

It is a historic, sad and very challenging day for Credit Suisse, for Switzerland and for the global financial markets, Lehmann said, adding that the focus is now on the future and on Credit Suisses 50,000 employees, 17,000 in Switzerland.