SoftBank will sell an extra 160 million shares in an IPO of its domestic Japanese mobile unit, which means it will end up raising JPY2.65 trillion ($23.5 billion), making it the country’s biggest IPO ever.

The figure is very close to an IPO by Alibaba in 2014 which generated $25 billion in 2014.

SoftBank chief Masayoshi Son had reportedly harboured hopes of surpassing the figure, which is reckoned to be among the largest floats in history. However, Son’s ambitions were apparently curtailed after major Japanese rival NTT Docomo announced it would slash fees by as much as 40 per cent, igniting concerns about a price war in the country.

Last month SoftBank had said it aimed to raise JPY2.4 trillion through the issue of 1.6 billion shares priced at JPY1,500 each, with a provision for an overallotment of additional shares worth JPY240 billion in the event demand is high.

A new filing to the finance ministry showed the indicative price remained unchanged and it exercised its overallotment option.

Reuters reported the deal’s domestic lead underwriters conducted an agressive marketing campaign for the IPO, including potentially the country’s first TV advertisements for such a move by a private company. More than 80 per cent of the deal was allocated to retail investors, the news outlet added.

The move also reportedly attracted young investors, some of which were participating in an IPO for the first time.

First officially announced in July, SoftBank’s IPO will help the company pay down debt, while also raising cash for its $100 billion technology Vision Fund, a long-term investment vehicle designed to enable the company to make big bets on future and emerging technology.