Montfort replaces Cubitt Consulting as the retained comms agency, and was appointed following a five-way competitive pitch.
The brief is to develop and implement an ongoing global comms programme for the group, which was created last November with the merger of Stonehage and Fleming Family & Partners. The company is to unveil a rebranding next Wednesday (9 September).
Montfort will be responsible for both internal and external comms, with a particular focus on EMEA.
Cubitt did not repitch for the account. Guy Hudson, partner and head of marketing at Stonehage Fleming, told PRWeek the ending of the relationship with the agency was "entirely amicable", saying the merger represented an "appropriate juncture to review the relationship".
Stonehage Fleming is said to be the largest independent multi-family office business in EMEA, working with more than 250 families and advising on assets worth around £27bn. It also deals with aspects such as its clients’ philanthropic ventures. The company employs more than 500 staff in 14 offices.
Hudson said: "The Stonehage Fleming team was unanimous in its decision to appoint Montfort. We were impressed by Montfort’s grasp of our vision for new combined group as well as its understanding of the opportunities and challenges that accompany such a merger."
Montfort was set up last year by M:Communications founders Nick Miles and Hugh Morrison. Collins, former MHP executive chairman, joined the group in early 2015.