DealsSheiner Will Exit Onex June 30 and Launch Altas Partners the Next DayAfter 17 years with Onex Corp., Sheiner to start his new firm, Altas Partners.ByLuisa Beltran26 June 2012•2 mins readJavaScript is required to read this article. Please enable it in your browser and reload the page.DealsNorth AmericaUS