HONG KONG, Nov. 7, 2007 (AP) -- Shares of Chinese e-commerce portal Alibaba.com Ltd. tumbled Wednesday following their stunning debut on the Hong Kong stock market the previous day.

The stock slid 17.5 percent to close at 32.60 Hong Kong dollars ($4.20) as investors sold to lock in profits after it nearly tripled Tuesday to HK$39.50 ($5.09) from its initial public offering price of HK$13.50 ($1.74).

Analysts warned the share could fall further.

"At above HK$30.00, Alibaba.com is trading at more than 200 times its 2007 price-to-earnings ratio. The valuation is still too expensive given its fundamentals and it has priced in all the good news," said Peter Lai, a director at DBS Vickers Securities Ltd.

Alibaba.com, one of China's fastest growing technology companies, raised a total of $1.7 billion in the initial public offering, bringing it close to the $1.9 billion raised by Google in its 2004 IPO.

The company initially raised $1.5 billion by selling 858.9 million shares, but late Tuesday exercised an overallotment option to sell an additional 113.7 million shares to raise another $197 million.

It was the third most actively traded issue on Wednesday, with 175 million shares trading hands.

Some analysts had cautioned that the stock was inflated even at HK$13.50 a share, but investors have been keen to tap the booming Chinese technology market.

Alibaba.com had 24.6 million registered members in 2007, up from 6 million in 2004. Paying members increased to 255,000 by June 2007 from 77,000 in 2004.