The trade surplus came to 807.1 billion yen (US$9.1 billion), a sharp rebound from a deficit of 75 billion yen a year ago amid the sharp global downturn, and the highest level since March 2008, the finance ministry said.

Japanese exports fell at their slowest rate in a year in October, down 23.2 percent from a year ago at 5.31 trillion yen, with sharp declines seen in vehicles and steel products.

The figure was an improvement on September's 30.6 percent decline.

"The main reason behind the strong exports was recovery seen in Asia," said Yoshiki Shinke, a senior economist at Dai-Ichi Life Research Institute.

"Japanese domestic demand is still weak. It's unlikely we'll see a robust recovery in Japan. But we should see a gradual recovery led by exports."

Imports were 35.6 percent below their level of October 2008 at 4.50 trillion yen, in part due to lower energy prices from last year, such as crude oil and liquid natural gas, the ministry said.

Japan, Asia's biggest economy, sank into its worst post-war recession in the second quarter of 2008 as the worldwide economic downturn hammered international demand for its cars, electronics and other exports.

It recovered this year, thanks in part to massive government stimulus spending, and posted a second straight quarter of growth in July-September, when the economy expanded 4.8 percent on an annualised basis.

With Japan's population ageing and shrinking, the country remains dependent as ever on foreign markets to drive growth.

"Japan is clearly participating in the global rebound, and its Asian neighbours in particular are lending it a helping hand," Adrian Foster, Asia head of financial markets research at Rabobank, told Dow Jones Newswires.

Japan's trade activity remained below the level of a year ago but is slowly recovering as the global economy pulls out of the doldrums.

Steps to revitalize overseas economies, including world leader the United States and Asian giant China, should sustain the recovery of Japanese exports, said Takuji Aida, senior economist at UBS Securities.

"With firm demand in China, the export recovery will continue, and we expect net exports will push up Japan's October-December gross domestic product," he said.