James joins from Costain where he was chief operating officer having spent 30 years at the contractor.
Kerr, said: “I am delighted with this appointment and welcome Darren to the Keltbray Group.
“He brings with him extensive experience across the key UK construction and infrastructure sectors where we operate.
“I look forward to him leading the team, driving growth through long-term client relationships and delivering on the potential that our unique capabilities create.”
James added: “‘I am delighted to be appointed chief executive of the Keltbray Group and am very much looking forward to working with my new colleagues, customers and stakeholders in meeting today’s challenges and unlocking the special potential the Group has delivering sustained growth going forward.”