Japan's merchandise trade surplus declined 11.8 percent in August from a year earlier to 614.8 billion yen for the second straight month of decline, as soaring crude oil prices boosted imports, the Finance Ministry said Wednesday.

Exports jumped 12.5 percent to 4.204 trillion yen, while imports surged 18.1 percent to 3.589 trillion yen, both rising for the 10th consecutive month, the preliminary report says.

A ministry official said imports will probably continue to outpace exports.