Antitrust authorities in Russia have decided to take on the US-based Internet behemoth Google. They charge the search engine giant with abusing its market position in the country by pre-installing Google-apps on smartphone devices.

The lawsuit was first launched by Google’s major Russian competition, the search engine Yandex. If Yandex wins its case, Google’s Russian operations could be forced to turn over as much as 15 percent of its revenue from 2014.

The Federal Antimonopoly Service of Russia argues that Google has broken a law regarding protection of competition. The FAS says Google must pay and change its ways or else risk greater fines in the future.

The revenue made by Google in Russia, and thus the exact figure for the fines it would have to pay, are considered trade secrets. The value will not be announced until September 28.

Yandex complained to the antitrust authorities that smartphones operating with the Android system, which is made by Google, came bundled with Google apps that optimized traffic to Google’s search engine.

As the news of the lawsuit broke, shares in Yandex rose by nearly nine percent.

“We believe the FAS decision will serve to restore competition on the market,” said Yandex. “In addition, the investigation confirmed the existence of agreements on prohibition of pre-installation of competitors’ apps.”

Since 2000, Yandex has dominated Russian markets thanks to its precise search results given in the Russian language. However, in recent years as Android-powered smartphones have gained popularity across the country, Google is beginning to eat into Yandex’s market share.

Google is currently facing similar anti-monopoly charges in the European Union.