U.S., Japan, W. Germany Exports Leap : Trade: Imports also are up in two of the countries. Inflation is lower in some industrial nations.

WASHINGTON — The United States, Japan and West Germany--the world’s largest trading nations--all showed a big increase in the value of their exports during the first half of this year compared with 1988, the International Monetary Fund reported Sunday.

West Germany’s exports increased from $159.1 billion to $169.1 billion; the United States’ rose from $157.6 billion to $182.7 billion; and Japan’s went up from $125.3 billion to $135 billion, the IMF said.

At the same time, West German imports rose from $124.1 billion to $132.7 billion and U.S. imports went from $224.6 billion to $241.5 billion. Japan’s imports dropped slightly, from $91.5 billion to $91.1 billion, the IMF said.

The U.S. trade deficit improved in the first six months to $58.8 billion, down from $67.1 the year before.

Japan’s surplus of exports over imports increased nearly one-third, to $43.9 billion from $33.7 billion. West Germany’s surplus increased to $37.2 billion from $34.9 billion.

Increased deficits were reported for Britain, $23.3 billion, instead of $21.1 billion; Italy, $10.3 billion, up from $6.8 billion; and France, $8.4 billion, up from $5.8 billion.

Total trade of 22 industrial countries rose to $2.1647 trillion from $2.0097 trillion for the six months.

The fund reported a drop in inflation among industrial countries in the summer quarter of the year, July to September. Prices paid by their consumers rose at an annual 4.5% rate against 4.8% in the spring quarter.

Third World countries, slower in their reporting, showed a slight drop in the annual rate for the April to June quarter: 62.7% instead of 63.8%. These figures vary widely from country to country: Brazil’s annual rate was 846.5% and Mexico’s 18.4%, while more prosperous countries in Asia had much lower rates, such as South Korea’s 5.7%.

The fund also noted a strengthening of the dollar in October. Compared to other major currencies, it was worth 4.42% more than in October 1988. In the same period, the Japanese yen dropped by 9.95%, the British pound by 7.96% and the Swiss franc by 4.26%.

The West German mark and French franc showed small increases.