SHANGHAI, Aug 24 (Reuters) - China"s coming rules for protecting critical information infrastructure are not aimed at firms planning overseas listings, and all companies must be involved in ensuring network security, a senior cyberspace regulatory official said. Sheng Ronghua, vice minister of the Cyberspace Administration of China (CAC), made the comments at a State Council briefing on Tuesday, when asked how the rules would affect such firms as well as those involved in foreign trade. read more The rules are to take effect on Sept. 1, the day when the country"s new data security law will also be implemented. "The rules are published to protect the safety of critical information infrastructure and all companies, no matter what kind they are or where they are listed, must comply with the country"s laws and regulations," he said. Chinese regulators have stepped up their oversight of internet platforms in recent months and have signalled that they want to sharpen their scrutiny of overseas listings. Last month, the CAC proposed draft rules calling for companies with more than a million users to undergo security reviews before listing overseas. The regulator has also launched a data-related cybersecurity probe into Didi Global (DIDI.N), citing a need to protect national security, just days after the company raised $4.4 billion in an initial public offering in the United States. Reuters reported last week that Chinese regulators are considering pressing data-rich companies to hand over management and supervision of their data to third-party firms if they want U.S. stock listings. read more