Norwich Union (NU) is to close 11 offices in the UK, at the cost of 750 jobs.
The decision is part of a restructuring process of its claims handling operation.
Another 11 existing claims centres will expand, creating 425 new jobs.
The claims offices to close are Basildon, Bristol, Cheadle, Chelmsford, Edinburgh, Nottingham, Croydon, Leeds, Bishopbriggs, Northampton and Luton. Other operations in these locations will not be affected.
The claims centres to expand are Exeter, Glasgow, Manchester, Preston, Bradford, Cardiff, Dundee, Southend, Newcastle, Liverpool and Ipswich.
The first closures will take place before the end of September.
Another 12 UK claims centres will maintain current staffing levels and all the centres in the restructured network will develop core areas of expertise such as household or motor.
Claims director Simon Machell said: "Any job losses are regrettable but we believe these changes give our remaining staff longer-term stability and the opportunity to develop specialist skills.
"By developing larger, more specialist sites, we can give brokers and customers easier access to better-trained staff who will have a greater depth of expertise in dealing with claims."
The restructuring process, which has about 18 months to run, will include investment in training and systems to boost specialist expertise.
The claims centres set to be maintained at current staffing levels are Belfast, Birmingham, Sheffield, Leicester, Southampton, Norwich, Worthing and Perth.
