TOKYO — The dollar dipped below 100 yen for the first time in 12 years today amid growing worries about a U.S. economic slowdown and expectations for lower U.S. interest rates.

The dollar fell as low as 99.75 yen, according to Thomson Financial, before bouncing back above 100 yen. It was the first time the Japanese currency had traded below 100 yen since November 1995.

The U.S. currency has been declining recently on growing speculation that the Federal Reserve will cut interest rates further to shore up the sagging American economy.

Weakness in the dollar is likely to hurt the profits of Japanese exporters by making their products more expensive abroad.

Players ranging from hedge funds to bankers to Japanese exporters have been selling the dollar.