Microsoft Corp, which lost its antitrust case with the European Union on Monday, was dealt another blow the following day when Timothy Chen Yongzheng - widely regarded as the company's most successful executive in Greater China - resigned to lead operations for the National Basketball Association (NBA) on the mainland. Mr Chen (right) will head operations on the mainland, Hong Kong, Taiwan and Macau under a new subsidiary - the first such enterprise formed in the country by a professional American sports league, according to the NBA. Microsoft said it had launched a global search for a successor to Mr Chen, 51, who joined the US software company in September 2003. Zhang Yaqin, 41, Microsoft vice-president and chairman of its China Research Development Group, will serve as acting chief executive for the company in Greater China until a new one is appointed. 'Tim helped achieve unprecedented business growth [for Microsoft in China],' said Microsoft International president Jean-Philippe Courtois. Mr Chen is credited with convincing Microsoft to pursue a strategy of co-operation and friendly engagement with mainland authorities and organisations, including top domestic computer makers Lenovo, Tsinghua, Tongfang and TCL. Since 1992, when Microsoft set up shop in the mainland, the company battled rampant software piracy and struggled to expand its business amid the rapid growth of the domestic personal computer market. Microsoft said its sales in Greater China have become the fastest in the world for the company during the past five years, and it has worked with authorities to promote legitimate software. It has increased staff to more than 3,200 from about 900 employees in 2004. Microsoft said it would invest US$100 million in mainland software firms, use another US$100 million on software and services development projects, and offer information technology training to 80,000 people between 2006 and 2011. Meanwhile, Mr Chen said he was optimistic about the NBA's prospects on the mainland, where basketball has become popular. 'The NBA is a truly exceptional brand with a huge fan base that reaches across all parts of China,' he said.