Softbank is reportedly in talks to take up a majority stake in co-working giant Wework, despite the firm tripling its losses last year.
Sources told Reuters the pricing and valuation of the deal has not been confirmed, while the Wall Street Journal earlier reported the investment could be between $15bn (£11.4bn) and $20bn from Softbank's Vision Fund.
The fund invested $4.4bn in Wework last year, with the company currently valued at $20bn as one of the top five most highly-valued private companies in the US.
Softbank Vision Fund and Wework declined to comment on the report.
The news follows the publication of Wework's accounts in Europe, which showed the co-working startup had tripled its losses in 2017 as it expanded heavily.
The situation has started to turnaround in London, however, where its flagship building Moor Place has made a small profit.
Shares in Softbank fell 5.37 per cent by market close in Tokyo overnight, as Reuters reported investors baulking at Softbank potentially increasing its already hefty exposure to technology stocks.
Softbank holds investments in the likes of Uber, self-driving unit GM Cruise, Arm, Improbable and Grab.