"After seeing there was no bargain hunting for the yen on its post-GDP slip, players bought back the dollar, which had retreated in New York," said Takashi Toyahara, forex manager at Nomura Securities.
The dollar/yen was also supported by a rise in euro/yen, triggered by stop-loss orders that drove the euro through key resistance levels, up nearly one yen to 136.90 yen from the day's low and a level not seen since January 10.
"It was an all-out yen weakness more than anything else," Toyahara said.
The dollar was around 105.10 yen up from 104.40 yen late in New York, while trading little changed against the euro at $1.3020
Traders said the market was still unsure of the dollar's medium-term direction, split between such supportive fundamentals as expectations for a widening interest rate gap and negative factors including concerns over the United States' huge current account deficit.
The uncertainty was reflected in a diverging dollar trend.
While the dollar has been mostly firm against the yen, it has weakened against sterling and the Australian dollar recently.
But it strengthened to $1.8915 to the pound and $0.7845 to the Australian dollar on Wednesday.
Earlier in the session the dollar's rise was restrained by Japanese investors' repatriation of US treasury coupon payments and Japanese exporters' selling, while it was supported by Japanese importers' buying at closer to 104 yen.
Traders said the market was squaring positions ahead of Greenspan's congressional testimony on the state of the US economy, with players looking for clues to market direction.