The firm said it expected the direct impact on its business to be "relatively minor", although the market uncertainty and impact on investor sentiment would likely hit investor flows across the industry.

"We have begun the process of applying to expand the scope of our Luxembourg-based management company to enable us to establish an asset management presence in the EU," the company said in an emailed statement, confirming media reports.

"This would involve us having some fund managers based in another EU country before the UK leaves the EU. We currently have investors in 12 locations globally, so we would expect this to be a smooth transition," it added.

Part of Ameriprise Financial, Columbia Threadneedle employs more than 2,000 people including more than 450 investment staff who collectively manage $464 billion in assets its website showed.

It says it is the 13th largest manager of long-term mutual fund assets in the United States and the 4th largest manager of retail funds in Britain.

(Reporting by Simon Jessop; Editing by Rachel Armstrong)