SoftBank Group Corp. is seeking to raise a record ¥2 trillion ($18 billion) from Japanese individuals in the initial public offering of its mobile phone unit, targeting investors who often get no interest on their savings, sources have said.

Nomura Holdings Inc., a joint global coordinator, will sell the biggest part of the shares to the retail investors, part of an IPO that could raise about ¥3 trillion in total, said the people, asking not to be named because the target is private. Tokyo-based SoftBank will announce the details for the debut sale as early as next week, they said.

The amount of IPO stock allocated to individuals varies from country to country — and indeed from offering to offering — with institutions often taking a majority and retail investors settling for the leftovers. SoftBank's target suggests the company's bankers anticipate strong demand from Japan's yield-starved individuals. Chief Executive Officer Masayoshi Son plans to pay healthy dividends to attract investors.