Reuters: Yahoo to pay $1 billion for Alibaba stake. Yahoo Inc. is close to paying $1 billion and forking over its China operations for a 35 percent stake of China’s second-largest e-commerce operator, Alibaba.com, a source close to the discussions said.
I know this is old news by now. You can find the Stock Purchase and Contribution Agreement between Yahoo! and Alibaba on the site now. There are additional Yahoo/Alibaba agreements on the Yahoo! contracts page.