Greece was also in the spotlight, as European Central Bank executive board member Joerg Asmussen said the central bank won't take part in any potential debt restructuring of the debt-laden country.

WSJ: European Markets Rattled

In a bid to restore confidence further, European Central Bank Executive Board member Benoit Coeure said Cyprus is a totally unique case, adding it would be wrong for policymakers to suggest otherwise.

WSJ: Greek Stocks Slump; Investors Play Catch Up on Cyprus Worries

In a bid to restore confidence, European Central Bank Executive Board member Benoit Coeure said Cyprus is a totally unique case, adding it would be wrong for policy makers to suggest otherwise.

WSJ: Greek Stocks Slump, Euro Steady

Yields in Spain and Italy, which had soared Tuesday, pulled back as investors took some solace from European Central Bank Executive Board member Benoit Coeure, who suggested that the central bank could turn to its bond-purchase program again to ease stress in Spain, where some feared the bond-market selloff would accelerate should 10-year yields top 6%.

WSJ: European Stocks Catch a Bounce

Britain will not get an executive board seat on the European Central Bank, and will be excluded from finance ministers' meetings on certain topics.

ECONOMIST: Tomorrow, perhaps