According to tradingmarkets.com Baidu Inc. (Nasdaq: BIDU | PowerRating) and Alibaba.com Ltd. (SEHK: 1688) are to take a stake in microblog of SINA Corporation (Nasdaq: SINA | PowerRating) involving an investment of USD 100 million.  Both, Baidu and Alibaba.com have declined comments on the story.  Alibaba.com however has started cooperation with SINA.  Source: Trading Markets