An Internet oligopoly is emerging among Chinese Internet enterprise such as Baidu, Tencent Holdings, and Alibaba, accounting for 70 percent of the total market value of all listed Internet companies in the country, Chinese website Hexun reported on Friday.

The stable monopolized positions of Baidu, Tencent Holdings and Alibaba in the areas of search engines, instant messaging and e-commerce pose challenges to the interests of Internet users, the prosperity of the industry and government supervisions, the report said citing a study by research firm Chinalabs.

The total market value of the three companies stood at $77.4 billion last year, according to Chinalabs.

While the market value of all listed Internet firms in China reached $110.5 billion by the end of November 2010, the value of the whole industry totaled nearly $150 billion.

In the third quarter of 200, the market share of Tencent, Baidu, and Alibaba in their areas stood at 76.56 percent, 72.3 percent and 54.39 percent respectively, Chinalabs said.