Phil Barton is to take on the role of Jelf CEO, succeeding Alex Alway who is to join the Marsh board as a non-executive director.
Marsh's £258m acquisition of Jelf was completed on 1 December.
Barton, who has been CEO of Jelf's insurance business since 2010, will also join Marsh's UK and Ireland executive committee and will report to Mark Weil, Marsh UK and Ireland CEO.
Barton, pictured, will lead a new structure at Jelf which will comprise three divisions: general insurance, employee benefits, and direct and partnerships.
Jelf's general insurance business will work closely with Marsh's existing business. The business will be led by Rob Worrell, currently Jelf Insurance trading managing director.
Marsh's existing broker networks and affinity businesses, together with the recently acquired SME Insurance Services, will become part of the new direct and partnerships division in Jelf and will complement Jelf's Purple Partnership and existing affinities business.
The employee benefits businesses of Jelf and Mercer Marsh Benefits will be combined to create a single business.
Within this, the small and medium-sized enterprise-focused unit will be led by Glenn Thomas, currently CEO of Jelf Employee Benefits. Jelf's Financial Planning business will transfer to Mercer.
Weil said: "We want to build on the well-known and respected Jelf brand by making it the basis for Marsh's offering to the UK's consumer and small and medium-sized commercial clients."
"Phil Barton has been a great leader in Jelf and I am confident that he, together with Glenn and Rob, will provide the leadership to drive this business forward. Alex has played a pivotal role in the growth of Jelf and in bringing our businesses together and, on the Marsh board, he will continue to help make the integration a success for our clients and colleagues," Weil added.
Barton said: "This represents a fantastic opportunity for us to build the UK's leading insurance and financial services proposition. The alignment and cultural fit between Marsh and Jelf has enabled the businesses to come together for the benefit of clients. This is a great vote of confidence in colleagues and our capabilities as a team."
