Chinese ride-hailing company DiDi Chuxing is investing an undisclosed amount in Estonian online taxi firm Taxify to help it expand in Europe and Africa, where it has gained share in some cities against US player Uber.

DiDi Chuxing will invest in and collaborate with Taxify to support the latter’s further expansion across its regional markets, the two companies said in a joint statement on Tuesday.

DiDi and other increasingly well-funded competitors in the ride-sharing business are seeking to grab share from Uber in regional markets around the globe, seeking to capitalize on the San Francisco-based firm’s recent, highly publicized woes.

Taxify said recently it had 2.5 million active passengers in around 25 cities and was gaining share against Uber in several markets in central and eastern Europe and, more recently, in Africa.

Since its founding 3-1/2 years ago, Taxify mostly has funded itself from operations, having only ever raised 2 million euros in outside financing from local venture capitalists and angel funders, Chief Executive Markus Villig told Reuters recently.

Uber operates in nearly 600 cities in 70 countries and reported it had fare revenues around $20bn last year. It was Silicon Valley’s most valuable private firm when it was last valued at up to $68 billion.

Over the past year, however, Uber has faced regulatory setbacks, employee and driver protests and executive departures, leading to founder Travis Kalanick being pushed out by the company’s board in June.

DiDi is the world’s second most valuable venture-backed start-up after Uber, having last been valued at $50bn according to venture investment tracking firm CB Insights, having raised $13 billion in funding over the past five years.

It counts 400 million customers in 400 cities in China. DiDi is backed by Chinese Internet giants Alibaba and Tencent and Japan’s SoftBank Group, among others. DiDi acquired Uber’s China business a year ago, leaving the U.S. online taxi pioneer with a minor stake in DiDi.

Uber also faces well-funded competition from rivals Lyft in the United States, Ola in India and Grab in south east Asia.

Last week, DiDi and SoftBank said they would contribute much of a new $2.5 billion investment into Grab, valuing the Singapore-based firm at around $6 billion.

Uber ceded control of its business in Russia and five nearby markets in July by agreeing to join forces with larger regional internet player Yandex, leaving the Russian company in control of the combined operation.