The dollar eased against the yen and euro in Asia on Friday as the market awaited a speech by the US Federal Reserve chief later in the day.
The greenback fetched 77.21 yen in Tokyo afternoon trade, down from 77.45 yen in New York late Thursday.
The euro firmed to $1.4424 from $1.4378 while staying almost flat 111.37 yen.
The dollar's fall came as investors continued to adjust bets ahead of Bernanke's speech to central bankers at Jackson Hole, Wyoming.
Any suggestion the Fed is mulling stimulus steps, even if not quantitative easing, could weigh on the dollar, dealers said.
Currency rates hardly moved after Japanese prime minister Naoto Kan made a long-expected announcement that he would resign as president of the Democratic Party of Japan, effectively ending his tenure as Japanese leader.
A new leader, the nation's sixth prime minister in five years, is expected to be elected next week.
The greenback was under pressure earlier this week on expectation that Bernanke would hint at fresh stimulus steps to bolster the sluggish US economy.
But market players grew sceptical that he would endorse a further round of monetary easing, in which a central bank buys assets from banks with electronically-generated cash to pump liquidity into the economy.
Source : New Age
