The dollar tumbled yesterday, but an official of a currency firm said it has about reached its lowest rate for the time being. Gold also fell in selling fueled by statements indicating the Federal Reserve has not eased its monetary policy.

Gold dropped $5 in Zurich to $450.50 an ounce. In London it closed at $451, down $6.50 from Tuesday's close. In New York gold finished $1.50 lower at $451.25 an ounce and settled on the New York Commodity Exchange at $451.30, down from $453.30.

Silver plunged to $10.915 from $11.115 an ounce and settled on the Comex at $10.958, down from $11.155.

In London the pound rose to $1.8490 from $1.8355, and it surged to $1.8590 in New York.

In Tokyo, where the markets were closed Tuesday, the dollar closed at 228.20 yen, off 3.35 yen from Monday, and it plummeted to 226.70 in New York.

PAN AM PAY CUT: Pan American World Airways' 1,055 British-based workers have accepted a 10 percent pay cut demanded by the U.S. airline to save jobs and reduce mounting losses, the company said yesterday.

Hank Auerbach, the airline's regional managing director, said British workers also accepted a wage freeze until the end of 1982.

A Pan Am spokesman said workers in 18 other countries had accepted the pay proposals, but balloting still was continuing among the airlines' 25,000 U.S. employes.