Postal Savings Bank of China announced Friday that it will sell 320 million extra shares to boost its sales to institutional investors in its colossal initial public offering (IPO) in Hong Kong. The 2.64% overallotment of the global offering will raise an extra HK$1.5 billion ($193.3 million) at a price of HK$4.76 per share, which will increase the amount of “H” shares 0.33 percentage points to 24.5% of the bank’s equity base, Caixin reports. According to the announcement on Friday, the extra funding will be used for sustainable business development. Postal Savings Bank, China’s largest bank in terms of network extent, raised $7.4 billion in the IPO at the end of September, selling 12.1 billion shares near the bottom of its indicative price range of HK$4.68 to HK$5.18 per share.