It appears that Mindray started new offering today. I read its SEC filings here. The insiders will sell 9,827,220 shares and the underwriter will have option to buy additional 1,474,083 shares from selling share holders. That alone won’t have dilution effect.
Separately, the company filed S1 form for stock options registration. That will dilute the stocks if option being excercised.
One thing I am not 100% sure is the difference between secondary offering and insider selling after lock up period (usually 180 days after IPO). I think this one belong to “secondary” because it’s not 180 days after its IPO yet (Sept 26, 2006).
(Update 01Feb07) FinanceAsia has more details about this selling.