International banking group, Citi, says its new investment arm has started trading across Europe out of Frankfurt, following its move there in anticipation of Brexit.

The finance giant said it has begun capital market activities and is carrying out services for clients across the bank’s entire markets and securities product offering.

The firm also said it has begun processing trades through the international Eurex Clearing system and is now offering its product and services from entities that will remain within the European Economic Area (EEA) after the UK leaves the EU.

"Since well before the Brexit vote in 2016, all our businesses have been focused on making sure we can continue to serve our clients in the UK and EEA, irrespective of the political outcome," said David Livingstone, Citi’s CEO for Europe, Middle East and Africa.

As well as being able to do business through the new Frankfurt based Citigroup Global Markets Europe AG, the bank says any clients who cannot work through its British based operations after Brexit can also use Ireland based Citibank Europe plc.

It has seen branches in 22 countries across Europe consolidated in the Dublin operation since 2016 and offers a range of different services.

Alongside moving operations to Frankfurt and scaling up its Dublin office, Citi has also signaled its intent to grow its offices in Amsterdam, Luxembourg, Madrid and Paris as a result of Brexit.

Speaking in Dublin last month, Citigroup CEO, Michael Corbat, said his firm would "plan for the best and prepare for the worst" in terms of what is to come.