Groupama has replaced Royal and SunAlliance as FirstAssist's payment protection insurance (PPI) underwriter.
The change of insurer is subject to High Court approval and will come into effect at the end of May. It is the final part of FirstAssist's separation plan.
FirstAssist, working in conjunction with Groupama Insurances, will continue to have responsibility for sales, marketing, pricing, administration, claims management and product development.
Pierre Lefèvre, chief executive of Groupama, said: “We are very pleased to have the opportunity to underwrite this substantial business portfolio. Groupama Insurances is keen to develop profitable niche opportunities and our relationship with FirstAssist can certainly help us achieve this objective.”