Concerns about Spain's high debts drove the euro down broadly on Thursday, pushing it to a three-week low against the dollar and spurring the Swiss National Bank to act to rein in the franc's strength.
Spanish borrowing costs rose as investors, following a poor debt auction on Wednesday, became increasingly nervous about the country's ability to meet budget targets that could mark another escalation of the euro zone debt crisis.
The SNB moved after the franc broke through a ceiling the bank had set last year against the euro zone common currency. Against the dollar, the euro was down 0.6 percent at $1.3064, having hit a three-week low of $1.3033. It also hit its lowest in four weeks against the yen at 106.86 yen before recovering to trade at 107.45 yen, still down 0.8 percent.