Updated

HSBC says its first-half profit declined 29 percent from a year earlier as uncertainty about China's economic outlook and Britain's relationship with the European Union fueled global market volatility.

HSBC Holdings PLC said Wednesday profit for the six months ending June 30 was $9.7 billion, or 32 cents per share, down from $13.6 billion in the same period of 2015. Revenue fell 10.5 percent to $29.5 billion.

In a statement, chairman Douglas Flint noted "spikes of uncertainty" about China's growth forecast and Britain's referendum on EU membership. He said that led to higher market volatility and lower customer activity, especially in Hong Kong, a key market for HSBC.

The London-based bank announced a $2.5 billion share buyback.