HSBC Holdings reported a surge in second-quarter net profit and announced a share buyback of up to $1 billion.

The London-based bank said Tuesday that net profit jumped 68% from a year earlier to $7.69 billion for the three months ended June. That beat the estimate of $7.36 billion in a poll of analysts by data provider Visible Alpha.

Last year's bottom line was weighed by $2.1 billion of losses related to associate Bank of Communications.

The bank said it plans to start a share repurchase of up to $1 billion, which it expects to complete by the time it announces third-quarter results.