China is opening an anti-monopoly probe into Microsoft

China, once the hottest growth market for United States technology companies, is turning chillier. In the latest sign of the change in climate, officials from a Chinese government agency that enforces antimonopoly laws and other business regulations visited four Microsoft offices across China on Monday, the company said. China is still one of the largest and most promising markets for United States tech companies, as well as home to the factories that make devices as varied as iPhones and Xboxes. But tensions between the United States and China have escalated over spying concerns by both sides. And in recent months Chinese authorities have increased their scrutiny of foreign tech companies. At the same time, they appear to be stepping up their use of laws to help bolster the fortunes of native technology companies. “The U.S. tech companies are much more concerned than they were two or three years ago,” said Robert Atkinson, president of the Information Technology and Innovation Foundation, a technology policy think tank. “Most of them were looking with growing interest at the China market. Now they’re much more concerned that the rug is being pulled out from under them.” The officials from the State Administration for Industry and Commerce visited Microsoft offices in Beijing, Shanghai, Guangzhou and Chengdu, Joanna Li, a public relations officer for the company, confirmed in a phone interview, answering questions about earlier reports in the Chinese news media. “There was a visit from government officials to our offices,” she said. “Given the sensitivity of the issue, I can’t say any more.”