Some 900 people were made redundant in 2010 when the company was in administration. It was subsequently taken over by US group Liberty in 2011.
At staff meetings, workers were informed that 140 redundancies would be sought in Blanchardstown in Dublin, 75 in Cavan town and 70 in Enniskillen. About 500 people currently work in each location. The company has told staff the development is necessary to secure the future of the company.
The redundancies are voluntary but the company has not ruled out compulsory job losses if the target is not reached.
It comes as the company plans to enter the insurance market in Northern Ireland and Britain.
In the past 12 months the company had serviced this business on behalf of the administrators of Quinn insurance.
In a statement, Liberty Insurance said a decision on redundancies was made to position the company for sustainable profitability and to protect the existing 1,100 jobs.
"We are fully committed to the Irish business, will continue to invest in our business, and believe that our arrival has been positive for the Irish Insurance market and consumers," chief executive Patrick O'Brien said.
Fianna Fail councillor David McGuinness expressed concern, saying: "Families with mortgages and young employees approaching Christmas now have this weight hanging over them."