The Maitland team will be led by partners Brian Hudspith and Liz Morley, consultant Tom Eckersley and analyst Helen Fickling.
The agency will report to Rebecca Salt, group comms director, and will look to highlight capabilities of Balfour Beatty in the global infrastructure market.
Salt commented: ‘As Balfour Beatty increases its strategic focus in new geographies, sectors and across all facets of the infrastructure mix, we have recognised that communications with key stakeholders will play a fundamental part in sustaining the future growth and development of the business.’
The firm, which had worked with Pelham since 2008, hired Salt to lead its global comms from CEVA Logistics in April.
Balfour Beatty built the £242m Aquatics Centre in Stratford, which will be a focal point of this year's Olympic Games.
The firm has also been awarded a £50m, ten-year contract to run services and facilities for the future Queen Elizabeth Olympic Park, including operating the 377ft-high observation tower, the ArcelorMittal Orbit.
In the past, Balfour Beatty has worked on major infrastructure projects including the Channel Tunnel and the M6 Toll.