Putnam, who joined as a graduate back when the business was Trafalgar House, will take up the new role from 1 October.
He takes over from Mats Williamson, who has been promoted to the main parent company senior executive team.
Putnam spent most of his career within the business, although he had a small break in the nineties at Balfour's piling firm Stent. During his last three years in charge of civil engineering and much of Skanska UK's building business, Putnam earned a reputation for delivering results and driving forward work safety.
Johan Karlstrom, president of Skanska AB, said: "I'm glad to see the turnaround of Skanska UK has been initiated. This work will continue, both in terms of profitability but also in the implementation of a common way of working in the unit."
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