Billionaire chief exec Masayoshi Son has publicly prodded ARM into going hell for leather on the Internet of Things, promising that the bought-out Brits would make a billion IoT chips by 2040, and separately from ARM has been inking the details on the $100bn Vision Fund, half of which comes from the Saudi state, with the other notable contributions coming from Softbank and Abu Dhabi.
When it bought Arm for £24 billion past year SoftBank promised to keep the Cambridge chipmaker, described as one of Britain's corporate "Crown Jewels", intact.
Both ARM and Softbank have refused to comment on the reports.
SoftBank pledged to embark on a major recruitment drive, doubling ARM's 1,600-strong United Kingdom workforce, while keeping its headquarters in Cambridge as part of its assurances over the takeover.
The biggest investor in the Vision Fund is Saudi Arabia's Public Investment Fund, which said past year it would contribute up to $45bn after protracted talks between Mr Son and Mohammed bin Salman, Saudi Arabia's deputy crown prince.
The stake sale coming so soon after Softbank's purchase could raise concerns over its commitments to the United Kingdom, but the FT said that Downing Street had been notified of the transaction and did not raise any concerns.
Masayoshi Son, founder and CEO of SoftBank, has nurtured the company into a global internet and telecommunication powerhouse, now aiming to fuse worldwide capital to go after further investments on behalf of his company.
On Wednesday, a Mubadala spokesman told Reuters that the talks were continuing and that the Abu Dhabi group hoped to resolve remaining issues in the next couple of days.
At the time, Theresa May said the deal was in the country's national interest. While completing the acquisition, the Japanese conglomerate made numerous commitments as a part of the deal, which included that it would keep the ARM headquarters in Cambridge.
In the post-Brexit climate, concerns were raised about "selling the crown jewels" of the British tech sector to a foreign investor.
In anticipation of the fund's first closing, Mr Son has been striking deals. In February, SoftBank said it planned to invest a further $1.7bn to merge OneWeb with Intelsat, another satellite company, if it persuades Intelsat bondholders to sign up to the deal.