Uber is merging its business in Russia with Yandex, a dominant player in the Internet business in that nation and Eastern Europe.

The move is an unusual one for Uber, a company that doesn't have a reputation for backing down against competitors. Still, Uber has become embroiled in internal controversy and litigation back home, and that has perhaps sapped some of the company's desire to compete in Russia and several other Eastern European markets.

The assets of the two companies will merge into a still-unnamed new company, with Yandex owning 59.3%, Uber owning 36.6%, and employees owning 4.1%, according to a press release sent out by Uber Thursday. The CEO of Yandex.Taxi, Yandex's ride-sharing division, will become CEO of the combined business.

In addition to combining forces in the Russian market, Yandex.Taxi and Uber will also join up in Kazakhstan, Azerbaijan, Armenia, Belarus, and Georgia. The combined entity will operate in 127 cities across those six countries, according to a presentation to investors that Uber has made public.

In addition to combining their assets, Uber will contribute $225 million to the combined entity while Yandex will contribute $100 million.

The other major market where Uber has taken a minority stake is China, where Uber sold its subsidiary to Chinese ride-sharing giant Didi Chuxing . Uber continues to own 17.5 percent of that business.

Yandex has been called the "Google of Russia" and has its hands in a variety of online sectors—including mapping, which will give it an advantage in ride-sharing.

"This combination greatly enhances Yandex's ability to offer better-quality service to our riders and drivers, to quickly expand our services to new regions, and to build a sustainable business," Yandex.Taxi CEO Tigran Khudaverdyan said in a statement.