Japan Post Holdings Co.'s underwriters will seek to attract retail investors to its ¥1.3 trillion ($12 billion) public offering, betting they will shrug off the stock's slack performance and market anxiety over North Korea.

The shares are being sold as the government continues its privatization of the postal and financial services giant.

The Finance Ministry will sell 990.1 million shares, including an overallotment, it said in a statement Monday. That amounts to ¥1.3 trillion, based on the most recent closing price.