Yue Xiu Group, a Guangzhou-based State-owned enterprise covering securities, futures, investment, financial leasing and other businesses, purchased 75 percent of the stocks of the Hong Kong-listed Chong Hing Bank Ltd on Thursday.
The deal was struck at HK$11.64 billion ($1.5 billion) for 326 million shares.
Chong Hing will remain a listed company on the Hong Kong Stock Exchange after the stock rights transfer.
Zhang Zhaoxing, chairman of Yue Xiu, said the purchase will raise financial centers in Guangzhou to a higher level.
"We will leverage the industrial financial resources held by Chong Hing to facilitate the stable and sustainable development of our banking system," Zhang said. "The purchase marks a step forward in the implementation of the Closer Economic Partnership Arrangement aimed at deepening the financial cooperation between the mainland, Hong Kong and Macao."