On Monday, Standard & Poor's said it may downgrade its rating on Greece's national debt amid mounting concerns about the governments ability to bring public finances under control.
The report weighed somewhat on the 16-nation euro, which bought $1.4803 Tuesday compared with $1.4823 late Monday in New York.
The British pound also fell to $1.6332 compared with $1.6439, while the dollar slipped to 88.94 Japanese yen from 89.48 yen late Monday in New York.
In the U.S., meanwhile, Federal Reserve Chairman Ben Bernanke said the U.S. economy will continue to struggle for some time.
Bernanke said in a speech Monday he thought the U.S. economy still faced "formidable headwinds" restrained by a weak labor market and tight credit, quashing hopes that the central bank would raise interest rates sooner than later.
Higher interest rates can support a currency as investors move funds to where they earn the best returns.