The world's five largest central banks, including the ECB, have agreed extra funding to shore up the financial system, amid fears of a fall out from the purchase by UBS of Credit Suisse.
Investors had feared another collapse like that of Lehman Brothers, the Wall Street giant whose failure sparked the global financial crisis in 2008.
Credit Suisse is the biggest name caught in market turmoil following the recent collapse of two American lenders.
Switzerland's president, Alain Berset, says the situation had become extremely dangerous.
"The takeover of Credit Suisse by UBS is the best solution to restoring the confidence that has been lacking in financial markets recently, and for best managing the risk to our country and its citizens."
