SoftBank Group Corp. is planning to raise ¥2 trillion ($18 billion) by listing shares in its telecom carrier unit on the Tokyo Stock Exchange by the end of this year, company officials said Monday.

The parent company is expected to retain roughly 70 percent of the SoftBank Corp. shares after the planned initial public offering on the TSE's first section, the officials said, adding that the subsidiary may also go public in London and other overseas markets simultaneously.

SoftBank Group is considering spending funds raised from the IPO on making new investments and paying back debt.