Japan Post Bank Co. plans to spend an initial ¥100 billion directly buying stocks — when it finds the right opportunities.

The nation's second-largest bank by deposits, which currently invests in equities only through passive investments in funds, is eventually aiming to boost active stock holdings to several hundred billion yen in the next five to 10 years, said Katsunori Sago, executive vice president at the Tokyo-based company.

Japan Post Bank is also looking to buy more higher-yielding overseas bonds and alternative assets as it seeks to boost growth in an environment where returns are being depressed by the central bank's policies of negative interest rates and yield-curve control. The company has about ¥2 trillion in stocks through its passive trust investments.