Pressure is being stepped up on foreign technology companies in China as the country's anti-monopoly agency announced an investigation into Microsoft.
The agency said it opened a case in June after complaints that Microsoft violated an anti-monopoly law by failing to publish all documentation related to its Windows operating system and Office software.
A preliminary examination failed to resolve the issue so regulators launched a formal investigation, the agency said.
Foreign technology suppliers face growing pressure from Chinese regulators, who have launched anti-monopoly investigations and announced plans to examine their products for security flaws.
In a separate case, state media said last week that regulators have concluded Qualcomm, a US-based chip maker for mobiles, has a monopoly but gave no indication what remedies they might demand.