The euro strengthened against the dollar for a second week as investors reduced record bets against the currency before Greece’s June 17 election, and amid speculation central banks may provide aid to financial markets.

The 17-nation currency pared earlier losses against the dollar on concern its decline since April has been overdone. Central banks are preparing for coordinated action to provide liquidity, if needed, after a general election in Greece in two days, Reuters reported. The dollar headed for weekly declines versus major peers as weaker U.S. growth added to the case for further monetary stimulus from the Federal Reserve.

The yen strengthened the most in two weeks against the dollar after the Bank of Japan refrained from expanding monetary stimulus that debases the currency. The central bank kept its asset-purchase fund at 40 trillion yen ($510 billion), matching the forecasts of economists.

The Dollar Index, which Intercontinental Exchange Inc. uses to track the greenback against the currencies of six U.S. trading partners, slipped for a fourth day, falling as much as 0.5 percent to 81.615, the least since May 23. It was down 1 percent for the week.