The contractor has been on site since the summer overseeing demolition and preparation work near Liverpool Street Station.
Mace has been confirmed as construction manager for the £340m new home of banking giant UBS by client British Land and Blackstone Group.
Mace has been managing the demolition of the existing 4 and 6 Broadgate buildings.
Mace’s chief operating officer for construction Gareth Lewis said: “Following our successful delivery of Ropemaker Place for British Land, we welcome the challenge of working with them to deliver another iconic building that sets new standards in green design and construction.”
Other design team members include Make as architects, Watkins Payne as building services engineer, Buro Happold as structural engineers, M3 as project managers and Sense, the cost consultancy arm of the Mace.