The U.S. dollar fell to its lowest levels since mid-March on most European money markets yesterday's, but dealers said trading was extremely light. The price of gold and silver rose sharply.

In Zurich gold closed at $518.50 an ounce, up from $507.50 at the close Wednesday. In London it closed at $522.50 against $507.50.

In New York gold surged to $529.50 an ounce compared with $507.50 Wednesday. The COMEX settlement price was $529.80, up from $507 the day before.

Silver rose to $14.75 on the cash market from $13.90 Wednesday and speculators on the COMEX settled for $14.67 an ounce, up from $13.64.

A New York dealer said much of the late buying came from overseas, "where there is increasing wariness over the possibility of military problems in the Middle East.

In Tokyo the dollar dropped sharply in response to the sale of yen-bonds to Saudi Arabia. The dollar plummeted to 244.85 yen, down 3.50 points from Wednesday's 248.35.In New York it fell to 244.15 yen.

European closing prices with late New York rates in parentheses were: Frankfurt, 1.8210 marks, down from 1.8305 Wednesday (1.8150); Paris, 4.24375 francs, down from 4.255 (4.2350); Zurich, 1.6975 Swiss francs, down from 1.7075 (1.6945); Brussels, 29.775 Belgian francs, down from 30.20 (29.07); Milan, 852.05 lire, down from 864.30 (815).

In London the pound edged up to $2.2655 from $2.2645, and it remained at the London level in New York.