SHANGHAI--Visual China Group, China's largest stock images provider, on Friday shut its website to make changes and apologized after it was criticised online and by regulators for selling images which it did not hold the ownership rights to.

The company, sometimes likened to U.S. photo agency Getty Images which it also partners with, apologized in a post on its official Weibo account, saying the incident revealed its weak management and that it was cooperating with authorities.

State news agency Xinhua said the company had been asked to meet the Tianjin city branch of China's Internet watchdog on Thursday evening and ordered to rectify its website.

Shares in the company slumped by their maximum 10 percent in early morning trading.

The topic "Visual China apologizes" was the most-read one on China's Twitter-like Weibo platform on Friday, with over 250 million views. According to its website, Visual China has over 40 million editorial images and 1.25 million videos.

Criticism of the company mounted on social media earlier this week after Weibo users posted that Visual China had indicated that it held the copyright for the first photo of a black hole, the result of research conducted by the Event Horizon Telescope project.

Other users later questioned its marketing of images of China's national emblems like the flag.

"The Visual China website, as reported by netizen, has issues with noncompliant pictures such as national flags and national emblems," the company said in the Weibo statement, adding that such photos had been provided by contractors.

"The company will learn from these lessons, seriously make rectifications, and voluntarily accept how the Tianjin Internet Information Office chooses to deal with the firm."

Political control of the Internet has tightened under President Xi Jinping, with demands that companies tighten oversight of "harmful information" which could range from vulgar to politically sensitive content.