Japan Post Holdings Co. said Thursday that it will sell up to 30 percent of its outstanding shares in subsidiary Japan Post Insurance Co. by the end of this month.

The value of the sale of up to 185 million shares will reach ¥440 billion based on the insurer’s share price Thursday on the first section of the Tokyo Stock Exchange.

Japan Post Insurance said the same day that it will buy back its own shares worth up to ¥100 billion between Monday and April 12.

Japan Post Holdings’ stake in the unit is expected to fall to about 65 percent.

The company plans to use the proceeds from the share sale for strategic investment to boost the group’s corporate value, officials said.

Japan Post Holdings is expected to use part of the funds to acquire a stake in U.S. insurance giant Aflac Inc. later this year, informed sources said. The postal service holding company announced the investment plan in December.

Japan Post Holdings plans to sell all of its equity stakes in Japan Post Insurance and another key financial unit, Japan Post Bank, based on the postal privatization law. It initially aims to lower the stakes to about 50 percent.

The planned partial sale of Japan Post Insurance shares is also believed to be aimed at demonstrating the progress in the privatization process of the country’s postal services and fending off criticism from the insurance industry that the group is pressuring private-sector businesses.