Yahoo shares fell as much as 8.6 percent on Wednesday after the controller of Alibaba Group, which includes China's largest e-commerce company Alibaba.com <1688.HK>, took full control of Alipay, a Chinese online payment business.

Yahoo holds a 43 percent stake in Alibaba Group, which is considered one of Yahoo's most valuable assets.

Yahoo disclosed in a government filing on Tuesday that Alibaba Group's online payment business, Alipay, was restructured so that all its outstanding shares are will now be held by Jack Ma.

Ma is the chief executive of Alibaba Group.

Alipay is a valuable asset, in our view, Stifel Nicolaus analyst Jordan Rohan wrote in a research note. Investors valuing Yahoo! on its sum of the parts will have to remove Alipay from the equation.

(Reporting by Jennifer Saba. Editing by Robert MacMillan)