The nation's surplus in merchandise trade soared 56.8 percent in July from a year earlier to 1.316 trillion yen, logging an increase for the 16th consecutive month, according to preliminary figures released Thursday.
The surplus figure for the month was the largest since December 1993, when a surplus of 1.407 trillion yen was recorded.
The economic slump led to a reduction in imports while the booming economies of the United States and Europe supported exports, a Finance Ministry official said. The trade surplus will probably continue to rise for the time being, but the pace of increase is expected to fall as the government's pump-priming measures are carried out, the official added.
The economic turmoil in the rest of Asia meanwhile continued to push down Japanese exports, bringing the nation's trade surplus with the region down 36.2 percent to 358.6 billion yen.
Overall exports on a customs-cleared basis came to 4.563 trillion yen, up 6.6 percent. Exports of automobiles, including expensive models, rose 10.8 percent in value terms but fell 3.3 percent in volume.
Overall imports fell 5.7 percent to 3.247 trillion yen, marking the seventh straight month of year-on-year decrease. Lumber imports fell 43.3 percent because of fewer housing starts in Japan. Crude oil imports decreased 12.1 percent in value as market prices plunged.
On a regional basis, Japan's trade surplus with the U.S. increased for the 22nd straight month, rising 59.7 percent to 669.7 billion yen. It was the largest figure recorded since September 1989, when the trade surplus figure came to 694.1 billion yen.
Exports to the U.S. grew 21.5 percent and imports from the country edged up 0.9 percent.
Major export items to the U.S. included cars, iron and steel, and auto engines. Car exports in volume actually decreased 3.2 percent, for the third consecutive month of decline, but increased 21.7 percent in value terms.