NEW YORK, SEPT. 2 -- The dollar closed lower today against all major foreign currencies, falling below the 1.80 level against the West German mark as central bank intervention failed to halt the slide.

Gold rose sharply.

The dollar dropped to 1.7965 against the mark, down from Tuesday's 1.8085. Earlier, in Frankfurt, the dollar fell to 1.8035 from 1.8106.

Traders said there was evidence that European central banks and the Federal Reserve were in the market supporting the dollar, although the level of intervention was believed to be minor. "It was small amount," said Jody Foulkes of Harris Bank in Chicago. "It was a showing of hands versus any real intervention."

The market, eager to test lower levels, "was encouraged by the unsuccessful central bank intervention," said Alfred Driever of Salomon Brothers Inc. "And the selling pressure will remain as long as the central bank intervention is not more successful."

The dollar fell to 140.85 yen from Tuesday's close of 141.50. Overnight in Tokyo, the dollar fell to 141.13, down 0.47 yen from the previous 141.60.

Dealers in Tokyo said intervention by the Bank of Japan to defend the dollar amounted to an estimated $200 million to $300 million.

Driever said that in order for the central banks to succeed in stopping the dollar's downward trend they "must come up with multiples" of the amounts committed in the last six or seven trading sessions.

In London, the pound climbed to $1.6505 from $1.6395 Tuesday. Later in New York, the pound rose to $1.6541, up from $1.6395.

Driever said the dollar came under pressure early in the day on comments from Helmut Schlesinger, vice president of the Deutsche Bundesbank.

Schlesinger "indicated that the Germans have adjusted to live with the mark at around 1.80," Driever said, "which could also mean around 1.75. And that did add to the pressure."

Other European closing rates with late New York prices and comparable Tuesday rates in parentheses:

Zurich, 1.4885 Swiss francs, down from 1.4935 (1.4830 vs. 1.4965); Paris, 6.0510 French francs, down from 6.0565 (6.0162 vs. 6.0650); Milan, 1,309.20 lire, down from 1,311.50 (1,301.25 vs. 1,312.25).

Republic National Bank in New York closed cash gold at $465.25 an ounce, up from its Tuesday close of $454.75.

New York's Commodity Exchange settled the spot contract at $465.30, up from $454.80.

In Zurich, gold rose to $464 an ounce, up from $453.50. In London, it ended at $463.75, up from Tuesday's $453.25.

Silver jumped to $7.79 an ounce from $7.34 on the cash market. It was settled it at $7.785, up from $7.327, on the Comex.

Earlier, in London, silver climbed to $7.735 from $7.33