Inter Hannover has agreed to acquire Congregational and General Insurance (CGI) from the Congregational and General Charitable Trust.
Terms of the deal have not been disclosed.
CGI is a church insurer in the UK, which is currently insuring several thousand places of worship, covering denominations and faiths.
It is also involved in insuring rectories, presbyteries and manses owned by churches.
CGI chief executive Carlo Cavaliere said: "We are delighted with the decision, having enjoyed several years of mutual success in building Integra with Inter Hannover as a strategic partner.
"Inter Hannover has a firm commitment to developing CGI’s position as a specialist church insurer and in doing so will be maintaining ongoing liaison and support links with the Charitable Trust."
Inter Hannover managing director Nick Parr said: "CGI’s excellent reputation, expertise and success are well proven and we see the acquisition as both business as usual and a focus for new propositions."
The deal is subject to approval by the Prudential Regulation Authority