QBE has announced its chief operating officer David McMillan will leave the company after two years to become CEO at a UK-based firm.
The UK insurer has not made an announcement yet but is expected to do so before the opening of the London Stock Exchange on Friday evening AEST.
Mr McMillan - who is already based in the UK - will continue to provide transition support over the next couple of months.
"David has played an important role in establishing the strategy of a stronger, simpler, more future-focused QBE," group CEO Pat Regan said in a note on Friday.
Mr Regan said Mr McMillan's resignation also provided the opportunity to make further organisational changes.
Chief information officer Matt Mansour, who joined QBE in 2018 from Barclays, will join the group executive committee, while group chief human resources officer Margaret Murphy will take on a broadened role as group executive of people and change.
QBE sharers rose 0.95 per cent to $12.76 by 1132 AEST on Friday and have climbed more than 25 per cent this calendar year.