NetEase, the mainland's largest online gaming operator, plans to spend US$100 million buying back its Nasdaq-listed American depositary shares after the stock has slumped 14% during the past two weeks. The buy-back, which will last three months, is NetEase's third after similar programs worth US$50 million last May and US$100 million last August, the South China Morning Post reported. The growth of NetEase has slowed as the popularity of its blockbuster games, Fantasy Westward Journey and Westward Journey Online II, have flattened. The firm also suffered a setback when Datang, a game it introduced last year, turned out to be a flop. Shares in NetEase have dropped 13.98% since February 26.