Investec today warned that its profit for the first half of the year was expected to fall on higher costs as the investment bank overhauls its business amidst uncertainties ranging from Brexit to the ongoing global trade war.
The company's shares fell as much as 10% in early deals.
Investec provides asset management and specialist banking services.
It has been streamlining its operations by selling and shutting some units and restructuring businesses in Ireland ahead of Britain's impending exit from the European Union.
"Market variability and persistent uncertainty relating to Brexit and global trade wars, has negatively impacted investment banking fees and trading income," Investec said.
It also warned that its UK specialist banking unit's profit would be "significantly" behind.
It now expects headline earnings per share to be 15% to 18% lower for the six months ending September 30, and said it would take a hit of about £42m to pretax profit in the period.
The company, which also has operations and a listing in South Africa, said its earnings were also hurt by the depreciation of the rand against the sterling.
Investec, founded in 1974, expects to float its asset management unit next year and said today the plan was on track.