Mitchell is stepping down to focus on the Tideway super sewer project in London is it moves closer to completion.
Reynolds will lead the industry’s chief body in partnership with construction minister Lee Rowley.
At the same time Richard Robinson, chief executive of Atkins UK and Europe, takes up the newly created deputy co-chair role.
Reynolds said: “The CLC, working in partnership with Government, provides crucial leadership to the sector.
“We do this most effectively where we speak to, and for, all parts of industry.
“While, I will continue the CLC’s focus on its four priorities, I would like to engage and listen to the wider industry over the summer to ensure we continue to deliver on the issues that matter most to us as a sector.
“I want to take this opportunity to encourage organisations across construction to get involved with the CLC’s work.”