Japanese investment in Southeast Asia continues to grow because of the region's potential and low labor costs and amid simmering tensions that have reduced the appeal of China for some businesses.

For a third straight year, in 2015 the amount of foreign direct investment from Japan to the 10-member Association of Southeast Asian Nations exceeded such investment in China and Hong Kong, according to figures compiled by the Japan External Trade Organization.

The pace has been accelerating — the outstanding amount of Japanese investment to ASEAN nations had almost tripled from five years ago to ¥20.1 trillion at the end of last year, according to Bank of Japan data.

Japanese investment growth to China slowed after protests there intensified in 2012 following a territorial dispute over Japan-held islets in the East China Sea, prompting companies to diversify investment risks.

With Japan's economic growth anemic and its population aging and declining, companies have been searching for growth opportunities elsewhere in Asia.

"ASEAN markets are attractive from the Japanese perspective,"' said Ma Tieying, an economist at DBS Group Holdings in Singapore. "Many economies have great potential to grow, thanks to relatively low per-capita incomes and a young population profile."

The openness of markets in the region along with labor costs that are lower than in China are also attracting Japanese investment, he said.

Of manufacturers responding to a 2015 survey on investment intentions, about 48 percent said they intended to strengthen or expand businesses in China, versus 73 percent in 2011.

The poll by the Japan Bank for International Cooperation found that about 56 percent of the companies want to expand investment in the five key nations of Singapore, Thailand, Indonesia, Malaysia and the Philippines. The other five members of ASEAN are Brunei, Cambodia, Laos, Myanmar and Vietnam.