The world's biggest internet search engine Google is failing to maintain its cyber grip in the world's fastest growing economy, China.

Chinese internet users in the metropolitan areas of Beijing, Shanghai and Guangzhou are turning instead to home grown rival, says the China Internet Network Information Center.

The search engine has increased its market share in the three cities by at least 10% in the past six months.

CNNIC reports Baidu now has 52% slice in Beijing, compared with Google's 33%. In Shanghai it has a 44% share and in Guangzhou it is 48%, compared with Google's 38% and 29% respectively.

Baidu made a big splash on the Nasdaq stock index in the US when it was listed earlier last month. It was valued at $850m ahead of its flotation and its shares, which sold for $27 each, quickly surged to $120, though have now dipped to around $83.

China's search engine market is expected to be worth about 3 billion yuan ($369m; €302m; £207m) by 2007, up from last year's value of 700m yuan. The number of internet users, currently around 100m, is expected to grow to 187m people by 2007.

Data sourced from BBC Online; additional content by WARC staff