Alibaba Group Holding Ltd. is seeking to raise as much as $21.1 billion in its initial public offering, in what could be the largest sale of new stock in the U.S. ever. The Chinese company and shareholders including Yahoo! Inc. (YHOO:US) plan to sell 320.1 million American depositary shares for $60 to $66 apiece, according to a regulatory filing today (BABA:US). At the high end of that range, the offering would surpass Visa Inc.'s $19.7 billion IPO in March 2008 and give the company a market value of $162.7 billion. Alibaba's executives are now able to meet fund managers to build demand for the IPO and they plan to begin the roadshow in New York next week, people with knowledge of the matter have said. The Hangzhou-based company has garnered years of attention for its scale — with 279 million active buyers in the year through June — and its exposure to a growing Internet consumer base in China.