Dai-ichi Mutual Life Insurance Co. said Tuesday it will transform into a stock company in April and seek to list itself, company officials said.

The decision was approved at a meeting equivalent to the general shareholders' meeting of a stock company.

Representatives of policyholders voiced concern over becoming a stock company and being listed on the Tokyo Stock Exchange at a time when the world is reeling from the financial crisis.

But Dai-ichi Mutual Life Insurance President Katsutoshi Saito stressed the need to make the changes.

"The domestic situation facing the insurance market will continue to be grim, and it is necessary to promptly make drastic reforms in its business structure," Saito said.

By becoming a stock company, the Tokyo-based firm will be able to procure funds from the market and invest in its future growth focusing on overseas operations, which would include actively engaging in buyouts.

In line with becoming a stock company, the insurer plans to allot some of its own shares to 3.06 million policyholders, in a move likely to make it the biggest in terms of shareholders of listed companies, surpassing that of NTT Corp.'s 1.27 million shareholders as of the end of March.

Dai-ichi will be the first among major mutual insurance companies to become a stock company. Smaller outfits, including Daido Life Insurance Co. and Mitsui Life Insurance Co., have already become stock companies.