The nation's current account surplus, the broadest measure of trade, decreased 17.6 percent in July from a year earlier to 1.08 trillion yen as imports outpaced exports, according to preliminary figures released Wednesday by the Finance Ministry.

The surplus in the current account, which measures not only trade but investment flows and cash transfers as well, has been on the decrease for three months in a row after a 40.2 percent rise was registered in April.

Factors underlying the recent shrinking surplus in goods-and-services trade -- the main ingredient of the balance -- are unlikely to change in the near future, a ministry official said.