HONG KONG -- Tencent Holdings has temporarily halted new sign-ups to the widely used Chinese version of its WeChat messaging app, in a sign of how Beijing's tightening regulatory net is affecting the country's tech giants.
Tencent said on Tuesday that new registrations for the Weixin messaging app, which has more than 1 billion users in China, would be suspended to facilitate a security upgrade to meet the latest legal requirements.
Tencent's stock, a pillar of Hong Kong's Heng Seng Index, tumbled 9% on Tuesday to HK$446 in its biggest fall since 2011. This added to a 7.7% slide on Monday.
The new suspension marks the first time that the super app, known overseas as WeChat, has halted taking in new users since its launch, also in 2011. Weixin previously conducted regular technological upgrades without having its operations interrupted.
"According to relevant regulations and laws, we are undergoing a security tech upgrade, during which registrations for personal and public accounts are suspended," Tencent said in its official account on social media platform Weibo, China's Twitter.
It said that the upgrade is expected to be completed by early August, when registration will resume. International sign-ups for WeChat will not be affected, a spokesperson at Tencent said.
The suspension came after Chinese regulators have significantly stepped up scrutiny on the country's largest tech companies and the way they collect and use personal data. Weixin is one of the most frequently used mobile applications in China, with over 1.2 billion monthly active users as of the first quarter of the year.
In addition to its core instant messaging function, Weixin also provides a wide range of services from online payment to financing. Many third-party operators such as Pinduoduo, the e-commerce group, also use Weixin's platform to reach users, giving the app access to massive amounts of user information.
This month China's cybersecurity regulator ordered Chinese ride-hailing app Didi to stop signing up new users, accusing it of wrongly collecting and mishandling personal data from its customers. The action came just days after Didi's $4.4 billion initial public offering on the New York Stock Exchange. Twenty-six of Didi's programs, including its main ride-hailing app, have been blocked in mobile app stores.
Following the action against Didi, the regulator announced that any Chinese companies holding data on more than 1 million customers would need its approval before seeking an offshore IPO.