Japan’s Trade Surplus Soars on Lower Imports : * Commerce: In a domestic recession, the country buys less from the U.S. but still sells abroad. Hence the growing imbalance.

Japan’s runaway trade surplus continued to gain steam in September, the Finance Ministry said Friday, nearly doubling from the same month a year ago as imports slumped.

The unadjusted surplus in the current account jumped to $8.83 billion from $4.63 billion. It reflects the trade gap in both physical items and such things as services, banking and tourism.

Japan’s trade surplus has long been a source of friction in relations with the United States.

Washington officials, noting that the United States runs a $50-billion annual trade gap with Japan, say Japan unfairly excludes imports.

And it was a fall in imports that caused the gap to widen in September.

“The surplus is going to continue to grow, but not because of exports,” said Paul Summerville, economist at Jardine Fleming Securities Ltd. in Tokyo. “We are seeing a collapse of import growth.”

Despite many economists’ predictions to the contrary, a Finance Ministry official said he did not believe that the recent rise in Japan’s trade surplus will continue.

“We don’t think Japan’s current-account surplus has structurally been on an up-trend,” he said.

The merchandise trade surplus was largely responsible for the gain. It climbed to $10.95 billion from $7.77 billion in September, 1990, with economists laying the blame squarely on weak import growth.

Imports sagged to $16.04 billion, against $17.39 billion in September, 1990.

While softer economic conditions have stunted demand for luxury goods such as European automobiles and art work, several one-time factors weighed heavily on the data.

In September, 1990, oil prices climbed in the lead-up to the Gulf War and gold imports were unusually high because many securities houses had set up gold-investment funds. Both sent imports up sharply, making this year’s imports look small in comparison.

Kazuko Mizuno, economist at Baring Securities (Japan) Ltd., said that as much as 90% of the drop in imports was due to distortions of a year ago.

As the full impact of Japan’s slowing economy continues to show up in the trade figures, however, imports will remain on a weak footing, Mizuno added.

On the other side of the trade equation, recent robust exports, which have drawn criticism from Japan’s trading partners, climbed to $26.99 billion from $25.16 billion a year earlier.

Economists attributed the slow growth to weak demand in Asia and Europe--two areas that had recently shown a healthy appetite for Japanese goods.

Asian economies are slowing down because of the recession in the United States. In Europe, economies have also been slowed by high German interest rates, economists said.

Kenneth Courtis, economist at DB Capital Markets (Asia) Ltd., said that while export growth was unimpressive, Japanese companies are winning market share overseas and are poised to sharply increase sales of products abroad when foreign economies start growing faster.

Elsewhere in the current account, the deficit in so-called invisible trade, which includes tourism, shipping and insurance, narrowed to $1.80 billion from $2.07 billion a year ago.

Economists said an increase in investment income was responsible.

In the first half of this fiscal year, Japan’s unadjusted current account widened to a $38.01-billion surplus from a downward revised surplus of $15.29 billion a year earlier.