Japan's current account surplus shrank 21.4 percent from a year earlier in September, the smallest drop since the March earthquake and tsunami, government data showed on Wednesday.

The surplus in the current account, the broadest measure of Japan's trade with the rest of the world, stood at 1,584.8 billion yen ($20.4 billion) in September, finance ministry data showed.

It was the seventh consecutive decline as the trade surplus fell in the wake of the March 11 disasters, which disrupted Japan's supply chains and hampered exports.

But the rate of year-on-year fall was the smallest, reflecting a recovery in the country's production and exports as it began recovering from the disasters. In August, Japan's current account surplus fell 64.3 percent from a year earlier.

The current account measures trade in goods, services, tourism and investment.