He will now be an ambassador for the law firm and be involved “in the strategic direction and decision making of the firm”.
Mr Green has been involved with Collas Crill for more than three decades and is a partner in the Guernsey property team.
“I am thrilled to start this new chapter of my professional life at Collas Crill,” said Mr Green.
“I am looking forward to being involved in the strategic decision making for the firm but also doing my best to raise the profile of the firm and supporting our partners, lawyers and support staff in their day to day lives at Collas Crill.”