This is because Arm’s customers view its semiconductor designs as an indispensable resource. They are used by more than 260 technology companies to make over 30 billion chips annually, powering 99 per cent of the world’s smartphones and everything from the tiniest of sensors to the most powerful supercomputers.

While an IPO investment would not come with a seat on Arm’s board or ability to dictate strategy, it could strengthen ties with each participating company and make it harder for a competitor to acquire Arm later, according to the sources.

“These guys want to be able to feed their technology needs back into Arm, so that their needs get put into Arm’s intellectual property,” said Jack Gold, founder of technology consultancy J. Gold Associates.

Arm and SoftBank declined to comment.

The details of the IPO discussions between Arm and its clients, which have not been previously reported, illustrate how the company’s neutral status as “the Switzerland of chips” remains a flash point. SoftBank is pursuing the IPO because its attempt to sell Arm to Nvidia for US$40 billion collapsed last year after other chip makers, who were clients of Arm, complained to antitrust regulators about it.

Nvidia is a major customer of Arm, licensing its technology to power a new processor for data centres that could win it market share against long-time rivals such as Intel and Advanced Micro Devices (AMD).

Nvidia declined to comment.

Another of Arm’s major customers in talks to invest in the IPO is Apple. It was part of a consortium that founded Arm in 1990, and has been using its technology for chips that power its iPhones and Mac computers. Its close relationship with Arm has helped it design chips that curbed its reliance on Intel as a supplier.

Apple representatives did not respond to a request for comment.

In its relationship with Arm, Samsung has also been motivated by its desire to have more autonomy and fewer costs in its production of smartphones. The South Korean company and its executive chairman, Jay Lee, have cultivated ties with SoftBank CEO Masayoshi Son, according to the sources. Son was born in Japan, but has Korean ancestors.

Samsung did not respond to a request for comment.

Intel has turned to Arm mostly to make custom networking chips. But as it expands its foundry business to compete in the contract manufacturing of chips against TSMC, it needs a closer relationship with Arm to ensure it can produce Arm-based chips for customers.

An Intel spokesman declined to comment.

Many technology companies that seek to make their own chips using Arm’s designs turn to TSMC for its low-cost manufacturing. This has motivated TSMC to advance the adoption of Arm’s designs.

TSMC did not respond to a request for comment.

Amazon has used Arm to develop its own chip called Graviton to power the servers behind its cloud business and reduce its reliance on Intel and AMD for chip supplies. It is seeking to expand the relationship as it develops more hardware, the sources said.

Amazon declined to comment.

Alphabet and Microsoft trail Amazon in developing self-sufficiency in chips, but are following suit. Alphabet is keen to secure supplies for its Pixel line of Android phones, while Microsoft wants to ensure compatibility with its Windows platform.

Alphabet and Microsoft did not respond to requests for comment.

None of these companies’ investments in Arm’s IPO are certain. SoftBank recently valued Arm at US$64 billion in a transaction with its Vision Fund, and it is possible that some companies will balk at the price expectations.

“The valuation seems kind of high and people are awaiting what valuation comes in at,” said Dylan Patel, chief analyst at semiconductor consulting firm SemiAnalysis.