Two regional directors of Carillion's M&E subsidiary Crown House Engineering have resigned.
Southern area director Bryan Williams and project director Bob King handed in their resignations two weeks ago.
The two are rumoured to be setting up their own project management consultancy, although both were unavailable for comment.
John Moore took over as Crown House Engineering's managing director last month, replacing Richard Lumby, who moved to head Carillion's infrastructure services business.Former Johnson Controls UK directors Bobby Ross and Ron Hillier are understood to have joined Carillion's facilities management operation. Ross and Hillier follow Don Kenny, who became managing director of the division last month.