The nation's current account surplus, the broadest measure of trade, fell 28.6 percent from a year earlier to 769.1 billion yen in October, according to preliminary figures released Monday by the Finance Ministry.
It was the first time in three months that the current account surplus, which measures not only trade but also investment flows and cash transfers, decreased on a year-on-year basis, the ministry said.
It is difficult, however, to say the current account surplus has entered a contraction phase, as October's decrease involves a rise and fall in various accounts, a ministry official said.
In October, high oil prices and computer imports for information technology-related investment became major factors in the shrinking surplus in the trade balance, pushing up the total value of imports to a record 3.39 trillion yen, the ministry said.
Japan's surplus in merchandise trade in October fell 32.6 percent to 873.5 billion yen.