CHINA Oilfield Services Ltd shares almost tripled on its first day of trading in Shanghai after investors ordered in excess of 300 times the shares offered by the unit of China's largest offshore oil explorer.

China Oilfield surged as high as 41.50 yuan (US$5.53) and tripled in value from their Shanghai IPO price of 13.48 yuan to close at 39.95 yuan today. The Beijing-based company will use the 6.74 billion yuan in proceeds from the sale of 500 million shares at 13.48 yuan each to buy ships and drilling equipment.

COSL, with China National Offshore Oil Corporation controlling 62 percent of its stake, issued 500 million yuan-denominated shares, or 11.12 percent of its total 4.495 billion shares.

The Shanghai listing will give mainland investors, restricted from directly buying Hong Kong stocks, a chance to own one of the best-performing stocks listed on the Hong Kong market.

COSL, Asia's largest oilfield services provider, in November 2002 issued 561 million shares, raising over HK$1.04 billion when it debuted on the Hong Kong Stock Exchange.

In the first half of 2007, COSL earned 1.1 billion yuan in net profits, up 63.4 percent over the same period last year. Its business volume rose 48.6 percent to 4.26 billion yuan. Full-year profits may gain more than 60 percent to 1.83 billion yuan, China Oilfield said in its listing prospectus.

Capital spending may be as much as 4 billion yuan a year between 2008 and 2010 as China Oilfield expands capacity, the company said on August 29.

A leading integrated oilfield services provider in China's offshore oil market, COSL operates offshore oil and gas prospecting, exploration and production services.

The other two Hong Kong-listed subsidiaries of CNOOC, CNOOC Limited and the Offshore Oil Engineering Co Ltd, are also preparing for a listing on the Chinese mainland stock markets, according to CNOOC deputy general manager Luo Han.

Oil demand in China, the biggest consumer of oil after the United States, will rise 5.9 percent to 7.6 million barrels a day this year, the International Energy Agency said in its September forecast. Oil has climbed 36 percent this year, peaking at an intraday record of US$83.90 a barrel on September 20.