By Nick Godt

The dollar fell against the Japanese yen while rising against the euro Thursday, with foreign-exchange traders playing off the European Central Bank's decision to leave interest rates unchanged and the Bank of England's move to boost its quantitative-easing program.

With stocks on Wall Street rallying amid upbeat U.S. economic data, pressure to sell the dollar remained in place. On Wednesday, the Federal Reserve maintained its pledge to keep interest rates low for the foreseeable future.

"Ahead of the G20 meeting, policy officials appear to be going out of their way to reassure markets that stimulus packages will remain in place until a sustainable recovery has been assured," said BNP Paribas in a note. Finance ministers and central bankers of the Group of 20 nations are scheduled to meet Friday and Saturday in St. Andrews, Scotland.

The dollar's drop against the yen picked up a little steam after the U.S. government said claims for unemployment benefits fell in the latest week, while productivity in the leading global economy rose more than expected in the third quarter.

The dollar bought 90.73 yen, up 0.3% on the day.

Meanwhile, the British pound first gained some ground before trading little changed against the dollar, after the Bank of England's decision to expand its quantitative-easing program by 25 billion pounds.

Some in the market had expected a bigger expansion of the program that buys up gilts and other assets. Interest rates in the U.K. were kept at a record low of 0.5%.

The pound (CUR_GBPUSD) rose 0.1% to stand at $1.6581.

Also Thursday, the European Central Bank kept its benchmark rates unchanged at 1%, as had been widely expected it would.

Speaking at a news conference after the decision, ECB president Jean-Claude Trichet said that risks to the outlook are "broadly" balanced and that he believes inflation expectations are firmly anchored.

The euro gained a bit of ground against the dollar, rising to $1.4874 after having been in negative territory earlier in the European trading session.

On Wednesday, the dollar lost some ground against major counterparts after the Fed left rates unchanged near zero and affirmed its commitment to exceptionally low rates as the U.S. economy seeks to stage a recovery.

In other dollar-related news, Deutsche Bank AG said the PowerShares DB US Dollar Index Bullish Fund (UUP) had run out of new shares and wouldn't be able to issue any more until its gets clearance from the Securities and Exchange Commission.

Several commodities ETFs suspended issuing new shares, amid regulatory examinations into their role in driving up commodity prices.