According to media reports, SoftBank Group is selling about one-third of its stake in the online car service Uber to make up for its loss of investment in Chinese online car service company Didi. SoftBank reportedly plans to sell 45 million shares of Uber over 30 days.

SoftBank began investing in Uber in 2018. The Softbank-owned Vision Fund invested another $333 million in Uber in 2019. The news led to a 4.31 percent drop in Uber shares in after-hours trading on the U.S. stock market on Wednesday.

A week ago, Uber's freight unit announced that it planned to acquire freight software company Transplace from TPG Capital for about $2.25 billion. Boosted by the news, Uber shares had a slight increase at the time.

On June 30, Didi was listed on the U.S. stock market, closing at $14.14 on its first trading day. Since then, the company's shares have fallen a cumulative 37 percent due to the regulatory crackdown of the Chinese government. During the same period, Uber shares fell about 8 percent.

SoftBank's Vision Fund holds a 21.5% stake in Didi after its U.S. IPO. According to U.S. media outlet CNBC, SoftBank lost about $4 billion on its investment in Didi.