Five of the world's 10 largest companies are now Chinese after China Life Insurance surpassed America's AT&T in market value.
This puts the Asian superpower ahead of the US, which has three companies in the top ten. China's stock rally has almost tripled its benchmark index this year,
prompting securities regulators to say that the market holds "great risks".
China's households are pouring more of their US$2.3 trillion ($3 trillion) savings into shares to beat inflation, which exceeds the return on bank deposits, and to profit from the world's fastest growth rate among major economies.
"China is one of the most exciting economies," said Jim Rogers, the chairman of New York-based Beeland Interests.
"The market is willing to pay a lot more for future growth."
Beijing-based China Life, the nation's largest insurer, gained 2.2 per cent in Hong Kong and added 5.3 per cent in Shanghai, valuing the company at 1.92 trillion yuan, or $3.3 billion.
San Antonio-based AT&T, the biggest US phone company, is valued at US$252.9 billion.
The People's Bank of China has told lenders to set aside more reserves eight times this year and has raised interest rates five times to help cool the economy.
China Life, PetroChina, China Mobile, Industrial and Commercial Bank of China and China Petroleum and Chemical Corp are now in the list of the world's 10 biggest companies by market value. Only two of those are in the top 50 by sales.
The three US companies in the top 10 by market value are Exxon Mobil, General Electric and Microsoft.
Russia's Gazprom OAO and The Hague-based Royal Dutch Shell Plc complete the list. Exxon Mobil retains its No 1 place.
The CSI 300 Index, which tracks yuan-denominated shares traded on the Shanghai and Shenzhen exchanges, has risen 169 per cent this year.
Hong Kong's Hang Seng Index, dominated by Chinese companies, has gained 57 per cent.
Bloomberg
