It wasn't the enthusiastic cheer you might've expected from a partner.

Asked about his company's joint venture with online-coupon website Groupon, the chairman of Chinese Internet giant Tencent Holdings replied in decidedly lukewarm terms.

'Groupon is our partner, so in a public setting we do not want to say much directly criticizing them,' Pony Ma said Monday at Disrupt, a conference hosted by Techcrunch at the China National Convention Center in Beijing, when asked about criticisms of Groupon and other foreign Internet companies looking to expand in China.

'We have an open attitude toward trying these new things, but once again it has proven that the China market is totally different from the U.S. or other markets,' Mr. Ma said.

The Wall Street Journal reported in August that the joint venture, which operates the website Gaopeng.com and is also funded by private-equity firm Yunfeng Capital, had closed offices in some cities and laid off hundreds of employees. Other U.S. Internet companies from eBay to Google have also had trouble expanding in China.

Mr. Ma did have some positive things to say about Groupon, arguing that the company had 'proved this is a good business model, providing online marketing to local companies,' and that the market for that service has good prospects.

But one problem is that competition is usually tougher in China than elsewhere, as 'dozens or even over a thousand' competitors will quickly crowd any new online industry, Mr. Ma said. 'The same night or even the same hour, Chinese companies... will all act at the same time' to imitate a new business model once it becomes known, Mr. Ma said.

Analysts estimate there are hundreds of online deals websites like Groupon operating in China, including Lashou Group, which last week filed with U.S. regulators for an initial public offering.

The Groupon-Tencent joint venture had a net loss of $46.4 million in the first nine months of the year on revenue of $2.1 million, according a Groupon regulatory filing.