Japan's current account surplus for September fell 31.1% from a year earlier, down for the second straight month, as the trade balance worsened mainly due to sluggish car exports and higher energy import costs, the Finance Ministry said Tuesday.

The current account balance, one of the widest gauges of international trade, marked a surplus of ¥1.0 trillion ($9.1 billion), logging a 15th consecutive month of black ink, the ministry's preliminary report showed. In August, the surplus posted a 21.8% decline.

The country's goods trade balance registered a deficit for the second successive month with ¥229.9 billion in red ink, down from a ¥906.7 billion surplus in the previous year.