The yen and dollar weakened after the Japanese and U.S. central banks pledged to keep interest rates near zero, boosting demand for stocks and higher-yielding currencies.

Especially the dollar fell against 12 of the 16 most-traded currencies a day after the Federal Open Market Committee left the federal funds rate target for overnight loans between banks in a range of zero to 0.25 percent, where it’s been since December 2008.

The Japanese and U.S. currencies fell also affected by the Bank of Japan doubling its loan program; aimed at countering deflation and the Federal Reserve yesterday retained a pledge to keep its target rate “exceptionally low” for an “extended period.”

The pound rose to the highest in almost three weeks versus the dollar after a report showed U.K. jobless claims unexpectedly fell in February at the fastest pace since 1997.

“Risk rallies because there was some residual disappointment that the Fed didn’t do more. We’re seeing dollar and yen weakness across the board.” said Elsa Lignos, a currency strategist at RBC Capital Markets in London.

The yen fell to 124.07 per euro from 124.31 yesterday in New York. It slid to 90.02 per dollar from 90.31. The dollar fell to $1.3815 per euro - the lowest since Feb. 9 -from $1.3766. Sterling jumped 0.57 percent to $1.5376, after trading at $1.5382, the strongest since Feb. 25.