HSBC, one of Britain's largest lenders, reported an on-year drop of almost 29 percent in first-half pre-tax profit, missing analysts' expectations.
For the first six months of the year, HSBC logged a pre-tax profit of USD 9.71 billion, down 28.7 percent from USD 13.62 billion in the same period a year earlier and the USD 10 billion figure estimated by analysts in a Reuters poll.
Revenue in the first half was down 4 percent at USD 27.86 billion.
The bank reported USD 3.61 million in pre-tax profit for the second quarter, a sharp decline from the previous quarter's USD 6.11 billion figure.
Hong Kong-listed shares were down 1.7 percent, unchanged from levels before the release.
The bank also announced it would conducting a share buy-back of up to USD 2.5 billion in the second half of 2016, adding that it would sustain its annual dividend at the the current level for "the foreseeable future."
Chief executive Stuart Gulliver wrote in a statement that the bank had performed "reasonably well in the first half in the face of considerable uncertainty," and that the reduction in profit reflected what had been a strong first half in 2015.
Investors will closely analyze the bank's outlook following the historic Brexit vote in June, which saw the U.K. vote to exit the European Union (EU).
Previously, HSBC said it may relocate staff to Paris should the Brexit vote go ahead, but Ivan Li of Tung Shing Securities doesn't believe that will happen.
"Maybe they will only move the department that deals with Euro zone-related trade," he told CNBC ahead of the earnings report.
In a statement alongside the earnings release, HSBC's chairman Douglas Flint said that the Brexit vote had brought about a "new era for the U.K. and U.K. business." But he added that HSBC's 150 years of experience in financing and facilitating trade had showed it the importance of an open trading relationship between the U.K. and the EU.
"Now is a time for calm consideration of all the issues at hand and careful assessment of how prosperity, growth and a dynamic economy for both the UK and the rest of Europe can be ensured following an orderly transition period," Flint wrote.
On the Brexit issue, Gulliver said it was too soon to know which parts of the business may be impacted by the U.K.-EU divorce.
"There has been a period of volatility and uncertainty which is likely to continue for some time," he wrote. "We are actively monitoring our portfolio to quickly identify any areas of stress, however it is still too early to tell which parts may be impacted and to what extent."
Li expects the dividend to be safe this year but warned that it could be cut over the next three to five years.
With two-thirds of its revenue coming from Asia, HSBC is generally shielded from some of the issues that have hurt rivals Lloyds and Barclays, said Martin Smith, East & Partners markets analysis.