Alibaba Corporation, web services operator Baidu, leading retailer Suning and investment holding company Tencent were fined 500,000 yuan ($78,200) for violating antitrust law.
China's State General Administration for Market Control detected illegal stock purchases by Meizu Technology Co., Yongyang Anfeng Technology Co. and AutoNavi Software Holdings Co.
Violations in the reporting documents of Baidu, Suning and Tencent were found, so fines were issued. Authorities have registered 43 cases of such violations recently.
Earlier PRC leader Xi Jinping announced government measures to curb market monopolization. The authorities want to protect small and medium-sized businesses.