Russian antitrust authorities ruled on Monday that Google broke the country’s competition rules, adding to the regulatory headaches the search giant is facing worldwide.

Russian officials said that Google had abused its dominant market position with Android, its mobile operating system, by favoring the company’s own services over those of rivals, including Yandex, a Russian competitor.

Earlier this year, Yandex had complained to the country’s competition authority that cellphone manufacturers were not able to include the company’s rival digital offerings in the Android operating system. After the complaint, the regulator began investigating whether Google unfairly bundled its own services, like digital maps, in its Android software.

Unlike in other parts of the world, where Google has outmuscled domestic search rivals, Yandex still holds more than a 50 percent market share in Russian online search, according to industry statistics. The company’s share price rose more than 8 percent in early afternoon trading in New York after the regulatory decision was announced.

Russia’s competition regulator will make the details of its decision public within the next 10 days, according to an official statement. Google may appeal the ruling. If the decision holds, the company may be forced to change what services it includes in its Android operating system as part of its efforts to comply with Russia’s competition rules, or face potential fines.

On Monday, the American tech company declined to comment on the Russian antitrust ruling, saying that it had yet to receive the decision.

“When we do we will study it and determine our next steps,” the company said in a statement.

Yandex welcomed the regulatory decision.

How Europe Is Going After Google, Amazon and Other U.S. Tech Giants The biggest American tech companies face intensifying scrutiny by European regulators, with — pressure that could potentially curb their sizable profits in the region and affect how they operate around the world.