Japan Post Insurance is shifting its approach to sustainable investing by picking companies with a technological edge for solving global problems, its investment chief said, in a move away from typical ESG selection criteria.

With total assets of ¥74.5 trillion ($670 billion), the life insurer also known as Kampo is one of Japan's biggest institutional investors and a major player in the world's third-largest stock market.

The firm plans to triple the portion of environmental, social and governance (ESG) investments in its domestic stock portfolio to around ¥100 billion over the next couple of fiscal years, starting in April, Chief Investment Officer Atsushi Tachibana said.