The euro declined from almost a seven-week high against the dollar and yen as a rise in Italian borrowing costs raised concern European Union leaders haven’t done enough to stem the region’s debt crisis. Europe’s currency weakened after posting its biggest gain in a year against the greenback yesterday, when leaders announced a way to prevent a Greek default and safeguard banks. Italian Prime Minister Silvio Berlusconi conducted the first test of investor enthusiasm for Europe’s debt since the summit’s plan was announced, selling bonds today at euro-era record borrowing costs.

The yen climbed toward a postwar record against the dollar, spurring bets Japan will intervene to weaken its currency. The yen is the biggest gainer among 10 developed-nation currencies in the past six months, rising 11 percent, according to Bloomberg Correlation-Weighted Currency Indexes. Japanese Finance Minister Jun Azumi said he will take “bold” action against the strong yen if needed.

IntercontinentalExchange Inc.’s Dollar Index, used to track the greenback against the currencies of six major U.S. trading partners, was little changed at 75.040, having dropped 1.6 percent this week on reduced demand for a refuge.