Japan's trade surplus jumped 12.5 percent in May from a year earlier, marking a second consecutive monthly increase, according to a preliminary report released Monday by the Finance Ministry.

Brisk exports to other parts of Asia were largely unaffected by fears over severe acute respiratory syndrome, the ministry says.

"The focus was whether SARS hit trade with China," said Tatsuya Torikoshi, a senior economist at the Daiwa Institute of Research Ltd. "But the trade figures of China, Hong Kong or Taiwan did not show much impact."