How does China Unicom go public in Hongkong?

China Unicom is a red chip stock listed in Hongkong. According to relevant information, China Unicom is listed in Hong Kong in the form of red chips, which means that the holding company is an overseas registered enterprise, but its business, profits, assets and management all come from Chinese mainland. In recent years, red chips have been widely used by mainland Chinese-funded enterprises, mainly private enterprises, and the scale of enterprises is generally small. A few state-owned enterprises, such as China Unicom and China Netcom, have been listed as red chips.