The trade surplus posted an increase of 1.6 percent in April from a year earlier, marking the first rise in two months, the Finance Ministry said in a preliminary report Thursday.
The small rise mainly came from brisk trade with other parts of Asia that have so far been little affected by the SARS epidemic. But analysts warn of a possible impact of the rapid spread of severe acute respiratory syndrome on Japan's future exports to China, which is an increasingly important trade partner.
Oil prices, which shot up ahead of the outbreak of the war in Iraq on March 20, have eased from the peak since then, limiting Japan's overall imports on a price basis in April and thus also contributing to the month's trade surplus.
The overall customs-cleared trade surplus -- exports minus imports -- stood at 840.4 billion yen in April.
The trade surplus with Asia surged 31.2 percent in the month from a year earlier to 415.8 billion yen, continuing a rising streak for 14 straight months.
Exports to the region rose 10.3 percent to 2.1 trillion yen due to a sharp increase in shipments of automobile parts and components of audio and imaging devices. Exports to China were up 39.5 percent at 550.5 billion yen.
Overall imports from Asia increased by 6.1 percent to 1.7 trillion yen due to a rise in petroleum products and crude oil.
On the other hand, the trade surplus with the United States dropped 11.8 percent to 568.3 billion yen, marking the fourth consecutive month of decline. It was dragged down by a decline in exports of automobiles amid a slowdown in the U.S. economy.
The trade surplus with the European Union was up 38.4 percent at 273.3 billion yen, buoyed by increased car exports to the region.