Japanese Central Bank Boosts Value of Dollar : Markets: The move allows greenbacks to rise against the yen. Price of U.S. bonds drops on foreign exchanges.

The U.S. dollar rose against the Japanese yen in foreign exchange markets Monday. U.S. bonds continued to drop in price in foreign trading, while Japanese stock prices jumped.

U.S. financial markets were closed for the Presidents’ Day holiday.

Foreign exchange dealers said the Japanese central bank aggressively bought dollars Monday to boost the greenback against the yen. The yen strengthened sharply last week after the two countries failed to reach agreement on cutting the U.S. trade deficit.

The yen’s rise is due to investors’ fear that the U.S. government will “talk up” the value of the Japanese currency in order to trim the U.S. trade deficit and pressure Japan to make trade concessions. A stronger yen makes Japanese goods more expensive in the United States and U.S. goods cheaper in Japan.

In Tokyo, the dollar closed at 105.23 yen, up 0.66 yen from Friday’s close. In London, the dollar was quoted at 106.30 yen, up from 104.15 on Friday. The dollar finished at 104.55 yen in New York on Friday.

Other dollar rates in Europe, compared to Friday, included: 1.7303 German marks, up from 1.7203; 1.4578 Swiss francs, up from 1.4490; 5.8837 French francs, up from 5.8383; 1.9416 Dutch guilders, up from 1.9270; 1,673.50 Italian lire, up from 1,668.00, and 1.3398 Canadian dollars, up from 1.3391.

The British pound was quoted at $1.4748, down from $1.4798 on Friday.

* In Tokyo, the 225-issue Nikkei stock average climbed 434.34 points, or 2.29%, to finish at 19,393.94.

“There was good reason to be positive,” said Raymond Bressoud of the Union Bank of Switzerland’s Tokyo branch. He noted that officials said a Cabinet-level meeting later this week will focus on steps to curb Japan’s trade surplus.

* Stock prices declined slightly in London, where the Financial Times-100 index fell 32.3 points to close at 3350.3.

Bond prices also fell. The price of the U.S. Treasury’s main 30-year bond was down 13/32 point, or $4.06 per $1,000 in face value, while its yield rose to 6.65%. That compares to a closing yield of 6.62% on Friday in New York. Prices and yields move in opposite directions.

Short-term Treasury securities fell 3/32 point to 1/8 point, and intermediate maturities fell 1/16 point to 1/4 point, the Telerate Inc. financial information service reported.

Commodity prices were mostly higher. North Sea crude oil for delivery in April rose 3 cents to close at $13.15 per barrel on the International Petroleum Exchange in London.

Gold closed in London at $379.95 an ounce, up $2.10 from Friday.

In Zurich, the bid price was $379.95, up $2.95 from Friday.

But in Hong Kong, gold fell $2.19 to close at a bid $380.97.

Silver traded in London at $5.17 a troy ounce, unchanged from Friday.