Alibaba.com Ltd. (1688.HK) said Thursday it has waived lock-up restrictions that required eight cornerstone investors in its initial public offering to hold onto their shares for two years.

Alibaba said in a statement the early release from the lock-up agreement took effect after the Hong Kong stock market closed Thursday and covers 157,760,000 shares, or 3.13% of its issued share capital.

Under the original terms of their investment, the investors would have been compelled to hold on to the shares until Nov. 6.

Alibaba Chief Financial Officer Maggie Wu told Dow Jones Newswires the move was intended to increase the liquidity of the company's shares and thus make them more attractive to institutional investors.

"It's hard for institutional investors to build a position. Buying a couple million shares a day, it takes a couple days to build a decent position," she said.

Alibaba shares closed at HK$14.02 Thursday, above their IPO price of HK$13.50 and up 151% year-to-date.

The cornerstone investors include Yahoo Inc. (YHOO) and AIG Global Investment Corp., a unit of the troubled insurance giant. They also include Foxconn (Far East) Ltd., a unit of Taiwan's Hon Hai Precision Industry Co., Cisco Systems International B.V., and Industrial & Commercial Bank of China Ltd.

Wu denied that Alibaba was freeing up the shares in response to investors who wanted to sell. Asked if AIG or others had asked Alibaba to be released from the lockup, Wu said "not at all. It's a very nice surprise to them."

Alibaba.com is the listed unit of Alibaba Group, which is 39%-owned by Yahoo.

Yahoo has an indirect stake in Alibaba.com through its stake in the parent, but also directly owns 1.14% of the listed entity.

Alibaba spokesman John Spelich said the change in the lockup period didn't indicate any intention for Yahoo to sell its stake. There has been speculation Yahoo may sell the stake, and its other Asian assets, since activist investor Carl Icahn suggested it last year.

Yahoo and AIG weren't immediately available for comment.

Wu also said the company has no plan currently to pursue any equity financing by issuing shares.

-By Aaron Back, Dow Jones Newswires; (8610) 6588-5848; aaron.back@dowjones.com