Alibaba buys controlling stake in digital marketing firm AdChina

HONG KONG (Reuters) - China's e-commerce giant Alibaba Group Holding Ltd said on Wednesday it had bought a controlling stake in online marketing company AdChina, an investment aimed at bolstering its advertising business. Alibaba did not close the size of the deal or the stake it would take in AdChina, a Shanghai-based firm founded in 2007. The internet marketing firm, which generated $51 million (34 million pounds) in sales in 2011, had filed for a $100 million initial public offering in F