The optical communications unit of television maker Hisense Group Holdings, Ligent Technologies, made a strong debut in Hong Kong, raising HK$5.6 billion (US$714 million). Shares of the fibre-optic communications equipment maker jumped as much as 19.2% on Tuesday morning, valuing the company at more than HK$35 billion. This adds momentum to a fresh wave of mainland Chinese conglomerates spinning off business units to tap overseas capital and support technology expansion.