Prices for platinum and palladium, which are key metals used in making automobile catalytic converters, fell 1 percent Monday in U.S. futures trading as a strong dollar and profit-taking dragged down all precious metals.

Platinum on the Comex was down $18.80 per troy ounce to $1,819.10, and platinum for immediate delivery fell $23.28 to $1,818.73.

Palladium on the Comex $14.75 to $723.85, and palladium for immediate delivery declined $14.60 to $722.80.

Both a rising U.S. dollar -- which reached its highest level against a basket of six major currencies in half a year -- and falling crude oil prices tend to weigh on precious metals' prices.

Besides the dollar and crude oil, investors went to their precious metals assets to cover heavy losses in stocks. In New York, the Dow Jones Industrial Average fell 65.58 points, or 0.60 percent, to 10,926.55 around 11:40 a.m. EDT. Germany's DAX fell 1.9 percent to 5,089.58 and London's FTSE 100 fell 1.4 percent to 5,141.98, both of which were down on a growing sense among some observers that Greece must either default or leave the eurozone, or both.