Gold prices tumbled nearly $7 a troy ounce in busy trading Friday to the lowest point in 18 months, hurt by a tide of fresh selling and evidence that inflation remains subdued.

The dollar was mixed in slow trading.Republican National Bank in New York quoted gold bullion at $411.75 as of 4 p.m. EDT, down $6.75 from its level of late Thursday and down $18.05 from late Wednesday, a combined loss of more than 4 percent. Gold had not traded that low since March 1987.

Bullion brokers said people who had hoarded gold as a hedge against inflation were becoming impatient and exasperated because the metal had been falling in value relative to some interest-bearing investments.

Moreover, recent economic statistics in the United States suggest inflation will not rise nearly as much as some gold holders had expected, heightening prospects that the metal could test $400 an ounce. Gold has not been that low since December 1986.

Gold fell in London to $412 from $417.75 late Thursday; in Zurich to $411 from $417.50; and in Hong Kong to $419.84 from $423.45. On the Commodity Exchange in New York, bullion for current delivery fell $6.90 to $411.70.

Silver fell on the London market to $6.40 a troy ounce from Thursday's $6.44 close. On the New York Comex silver for current delivery fell 14.1 cents an ounce to $6.326.

In foreign-exchange trading the dollar varied slightly in value, reflecting what money brokers called an uncertain outlook for the U.S. currency and resilient fear of central-bank intervention to keep the dollar stable.

In Tokyo, the dollar rose 0.31 yen to 133.76 yen. Later in London it strengthened to 134.25 yen. In New York the dollar fetched 134.12 yen, higher than its 133.77-yen level late Thursday.

The British pound strengthened against the dollar to $1.6758, vs. $1.6675 late Thursday. In New York, the pound sold for $1.6787, marginally weaker than its $1.6790 level late Thursday.

Other late dollar rates in New York compared to the levels of late Thursday: 1.8711 West German marks, down from 1.8747; 1.5807 Swiss francs, down from 1.5823; 1.2232 Canadian dollars, up from 1.2225; 6.3630 French francs, down from 6.3763; and 1,399.00 Italian lire, up from 1,398.70.

Other late dollar rates in Europe compared to late Thursday: 1.8763 marks, down from 1.8775; 1.5835 Swiss francs, up from 1.5820; 6.3795 French francs, up from 6.3790; 2.1151 Dutch guilders, down from 2.1160; 1,398.50 Italian lire, down from 1,398.87; 1.2232 Canadian dollars, up from 1.2225.