Investment company Fosun International (0656.HKG) has offered to buy the remaining 80% of US insurer Ironshore (IRSH.NYSE) for US$1.8 billion, Reuters reported, citing an announcement to the Hong Kong Stock Exchange. Fosun owner Guo Guangchang’s conglomerate is among the most acquisitive and agressive private-sector firms, having previously already launched about US$6 billion worth of deals this and last year. Fosun has identified insurance as a major growth area, having bought the insurance arm of Portuguese state bank Caixia Geral de Despositos SA for EUR1 billion (US$1.1 billion) in 2014.