Kamtech Services Inc.
ERDC Ltd.
HPN
H.A., Simons Overseas Ltd. (1979-1981)
H.A., Simons Overseas Ltd. (1976-1978)

ERDC Ltd
  - Red Dog Mine
  - Simpson Paper Company Plant

Gotaverken Energy Systems Ltd.
Chas T. Main Inc.

ERDC Ltd.
  - Burns & McDonnell
  - Abitibi Pulp & Paper Mill
  - Geco Wilroy Project
  - Kamtech Services
  - KEI Construction
  - Ahlstrom Machinery Group (1999)
  - Ahlstrom Machinery Group (1997-1998)
  - REPAP

Chas T. Main Inc.