The private equity-backed buyout of Canopius has now completed returning the Top 10 Lloyd’s insurer to a standalone business.
The $952m (£737m) deal between Sompo Holdings and a consortium led by Centerbridge Partners was first announced in September 2017.
The Japanese firm had bought Canopius in 2014 for £594m.
Canopius will be led by chairman Michael Watson and group chief underwriting officer Mike Duffy.
Since being founded in 2003 Canopius has grown to write over $1.5bn of premium last y