Capita said the acquisition of GL Hearn would allow it to build on the offer provided by its existing property and infrastructure business, which employed 78 chartered town planners according to Planning's 2014 consultants survey.
GL Hearn has 250 staff in London, and seven regional offices including Glasgow, Manchester and Southampton. Planning's 2014 consultants survey showed it had a planning staff of 94, of whom 48 were chartered town planners.
Capita chief executive Andy Parker said GL Hearn would be a "transformative addition" the business.
"Beyond extending and enhancing our existing real estate offer, GL Hearn’s track record and range of expertise will allow us to provide market-leading commercial, technical and strategic advice across the entire development process," he said.
GL Hearn managing director Brian Sloggett said Capita’s purchase represented "an exciting new phase" that would accelerate the business’ growth potential.
Capita has partnerships to provide planning-related services at several English local planning authorities, including the London Borough of Barnet, North Tyneside, and Salford.
A Capita spokesman said there were "no redundancies on either side" as a result of the acquisiton.