Chinese software firm Kingsoft announced the formal resignation of its CEO, Lei Jun, for health reasons on Thursday, China Business Net reported (in Chinese). The company said the news of Lei's sudden departure "was a shock." Lei, who built Kingsoft into a leading software developer during his 16 years at the company, denied rumors of disputes between him and company founder Qiu Bojun. Kingsoft's stock price on the Hong Kong Stock Exchange went up 1% to HK$4.04 (US$0.52) following the news.