The insurer bought 10.8 million shares at an average price of HKD28.29 (2.9 pounds) per share on Sept. 23 via investment management arm, Ping An Asset Management Co Ltd, it said in a filing to the Hong Kong stock exchange late on Friday.

Before the latest transaction, Ping An held a 7.95% stake in the bank, the filing showed.

The Chinese insurer began buying shares in the bank, which makes the bulk of its revenue in Asia, in 2016 as part of its insurance investments and in December 2017 passed the 5% threshold after which it had to announce its holding.

Ping An gradually kept increasing its holding in HSBC, which is also listed in Hong Kong, and in late 2018 it became the biggest shareholder in the London-headquarter bank, replacing BlackRock Inc.

HSBC has been facing mounting pressure in recent months from lawmakers in the United States and Britain who are critical of Beijing's handling of the democracy movement in Hong Kong.

Senior British and U.S. politicians have criticised HSBC and Standard Chartered, which also makes most of its sales in Asia, after the banks backed China's national security law for the territory.

(Reporting by Sumeet Chatterjee; Editing by Stephen Coates)