June 21 (Bloomberg) -- Japan's export growth almost doubled in May, buoyed by shipments of cars and electronics to China and the European Union.

Exports rose 15.1 percent from a year earlier, compared with 8.2 percent in April, the Ministry of Finance said today in Tokyo. The gain beat economists' estimates, helping the trade surplus widen 9.3 percent to 389.5 billion yen ($3.2 billion).

Faster export growth and a recovery in spending by consumers at home will help sustain the economy's longest expansion in more than 60 years. Shipments to Europe rose at the quickest pace in nine months, helped by the yen's drop to a record against the euro, and exports to the U.S. rebounded after dropping for the first time in two years in April.

``Exports overall continue to be solid, carried by increased shipments to Asia and Europe, and the yen's weakness is no doubt a help,'' said Junko Nishioka, an economist at ABN Amro Securities Japan Ltd. ``The worst seems to be over in the U.S. and that's a good sign for Japan.''

The yen traded at 123.64 per dollar at 11:33 a.m. in Tokyo compared with 123.54 before the report was published. The surplus rose less than the 462.7 billion yen median estimate of 36 economists surveyed by Bloomberg News.

Imports climbed 15.5 percent to a record 6.18 trillion yen, the Finance Ministry said, as the weaker yen increased the cost of goods purchased from overseas. Economists predicted imports to rise 10.3 percent and exports to increase 11.8 percent.

Weaker Yen

The yen traded at an average 120.76 against the dollar in May, 8 percent lower than the same month a year ago, according to Bloomberg data. A weaker currency increases import prices, causing oil products to rise in yen terms even though they declined in dollars, the ministry said.

Net exports -- the difference between exports and imports -- were the biggest contributor to growth in the first quarter, helping Japan's economy expand at an annual 3.3 percent rate. The U.S. economy, the world's largest, only expanded 0.6 percent in the period, the slowest pace in four years.

Shipments to China climbed 24.5 percent, the quickest rate in four months, to 1.03 trillion yen. Exports to the U.S. gained 0.4 percent to 1.30 trillion yen after declining 5 percent in the previous month, the first drop since January 2005.

Exports to the European Union surged 17.9 percent, the fastest pace since August, to 971.1 billion yen. The volume of exports to Europe surged at the fastest pace in almost a year, suggesting shipments to the region are being fueled by stronger demand and not just a weaker yen.

U.S. Rebound

U.S. growth is showing signs of accelerating. The Institute for Supply Management's factory index for May rose to the highest level in 13 months, and orders for business equipment climbed for a second straight month in April.

``We did have a big inventory adjustment in the U.S. in the first quarter but now a lot of indicators in terms of orders are turning around,'' said Amy Auster, head of international economics at Australia & New Zealand Banking Group Ltd. ``Japan's own export orders are actually looking fairly good.''

Automakers may be able to count on higher demand in coming months. Honda Motor Co.'s exports rose 1.2 percent in April, accelerating from the slowest pace in 10 months, according to the most recent figures.

Honda's sales in China surged 33 percent in May, led by a fivefold increase in demand for its Civic compact car. The Tokyo-based automaker's sales in Asia's fastest-growing major economy are up 39 percent this year.

Lower Volume

Still, some economists say exports are being propped up by the weaker yen and demand from the U.S. will remain slow in the coming months. Japan's currency fell to a 4 1/2-year low against the dollar this week and an all-time low of 166.12 per euro.

``Exports have been supported by a weaker yen, and the volume of shipments is decreasing,'' said Takeshi Minami, an economist at Norinchukin Research Institute in Tokyo. ``It'll take a few more months for the U.S. economy to gain momentum and for exports there to pick up.''

Shipments to the U.S. measured by volume fell 13.2 percent in May, little changed from the 13.1 percent drop in April, even as exports in yen terms rebounded last month.

To contact the reporter on this story: Lily Nonomiya in Tokyo at lnonomiya@bloomberg.net

Last Updated: June 20, 2007 22:35 EDT