SoftBank Vision Fund is selling $245m of shares while PayPal is investing $500m in the ride hailing service, in the world's largest IPO since 2014.
Uber is set to raise $7.9bn to $9bn if it floats within its range, while PayPal has agreed to invest another $500m through a private placement.
SoftBank Vision Fund and Alphabet are among the largest shareholders in Uber, which has filed for an offering that could value it at $100bn, a decade after it was founded.
Careem has agreed to an acquisition by Uber in a cash-and-convertible note deal, allowing Rakuten, Al Tayyar, Daimler, STC and Didi Chuxing to exit.
Lyft has set the range for an IPO that would allow Alphabet, Rakuten, GM, Jaguar Land Rover, Alibaba, Didi Chuxing, Magna and Icahn Enterprises to exit, valuing it at up to $22.9bn.
SoftBank Vision Fund invested $1.46bn to take Grab's series H round, already backed by Toyota, Hyundai, Kia, Booking Holdings, Central Group, Yamaha, Ping An, Microsoft, Tokyo Century and KBank, to $4.5bn.
Rakuten, General Motors and Alphabet own a combined 26% share of the ride hailing platform, which has filed to go public and which was valued at more than $15bn as of last June.
Amazon has led the electric truck developer's latest round, which featured existing backers likely to have included corporates Abdul Latif Jameel and Sumitomo.