Policies from Malta, France, Germany and Ireland would all transfer to its Irish company, Prudential International Assurance PLC (PIA), from the UK-based Prudential Assurance Company Limited (PAC).

Business currently being written through a Polish branch of PAC would transfer to a new Polish branch of PIA, the company wrote.

"This means that PIA will become Prudential's main insurer in the EU," the letter said.

The plan is currently being cleared by regulators and the courts and is due to go live at the start of 2019, a spokesman for the company said.

Prudential has had a licensed entity in Dublin since 1994 and most of its insurance sold offshore or in Europe is already written there, he said.

A number of the books of business being moved were closed to new business, he said, adding no personnel would need to be hired or move from Britain to Ireland as a result of the change.

(Reporting by Carolyn Cohn and Simon Jessop; editing by Maiya Keidan and Kirsten Donovan)