Alibaba Group Holding Ltd agreed to buy Youku Tudou Inc, known as China’s YouTube, for about $3.67 billion, slightly more it had offered in October. Youku Tudou’s American Depositary Shares were up 8.3 percent at $26.50 in premarket trading on Friday, below the e-commerce giant’s offer of $27.60 per ADS. Alibaba held 18.3 percent of Youku Tudou as of Oct. 16, when it made its initial offer of $26.60 per ADS.