Croot was hired by Barclays in 2010 after working on the bank's account for financial PR agency Brunswick, where he had worked for more than ten years as a director.
Before Brunswick Croot was news editor of ITN.
In his new role Croot will lead media, investor relations, internal comms and public affairs. He will report to Balfour Beatty Group chief executive Leo Quinn.
Croot told PRWeek: "Balfour Beatty is a world-leading brand. I’m looking forward to helping build its reputation as an expert global infrastructure company with a high-performing global communications and investor relations team.
"Communications and investor relations will play a core role in helping Balfour Beatty to convey its strategy and vision to all our stakeholders throughout a critical business transformation programme."