Companies were fined 500,000 yuan ($77,000) each, according to the statement.
Baidu, ByteDance, Didi and SoftBank did not immediately respond to requests for comment.
China has stepped up its scrutiny of the country’s internet giants in recent months and has in particular cited concerns over monopolistic behaviour and potential infringements of consumer rights.
($1 = 6.49 Chinese yuan renminbi)
(Reporting by Yingzhi Yang, Cheng Leng, Pei Li, Yilei Sun and Tony Munroe; Editing by Christian Schmollinger and Karishma Singh)