According to the group, the move signals its intention to seek further acquisitions in the country.
Finbarr Crotty, Eoin Greene and Graham Devine will all continue as executives, directors and shareholders in the business, supported by their current members of staff.
As part of the next stage of the company’s development, Crotty will move to executive chairman while Greene will become CEO.
Stephen Ross, head of mergers and acquisitions for GRP, said: “We’re delighted to be bringing such a well-respected and successful business on board and to be entering the Republic of Ireland’s thriving insurance sector.
“Finbarr, Eoin, Graham and their team have rightly earned a strong reputation for their depth of expertise and the great service they provide to their clients.”
Crotty said: “This is a fantastic development for us and our customers. We have worked very hard to build a successful business and earn our reputation in the market and we’re delighted that GRP has recognised the value of what we’ve achieved.
“We have been very impressed by GRP as an organisation and are really excited about the value our new partner will bring to our clients and employees.”
Mike Bruce, Group CEO at GRP, added: “We’ve always seen Ireland as a great opportunity to grow the business beyond the UK, so we’re very pleased with this deal and look forward to further growth in the ROI market.”