Volker Kier

Ed. Züblin AG engages in the provision of building construction and civil engineering services. Its services include turnkey construction, structural maintenance, tunnelling, ground engineering, structural steelwork, timber construction, environmental technology, bridge construction, chimney and refractory engineering, construction logistics, and modular construction . The company was founded by Eduard Züblin in 1898 and is headquartered in Stuttgart, Germany.

STRABAG AG provides building, construction, and technical services. The firm engages in the design, planning, billing, and construction of structures and technical installations. It also sells and distributes building components, materials, and equipment. The company was founded in 1895 and is headquartered in Cologne, Germany.

BAU Holding Beteiligungs AG designs and constructs expressways and roads. The company was founded in1999 and is headquartered in Spittal an der Drau, Austria.

oekostrom AG für Energieerzeugung und -handel engages in the construction and operation of installations for the use of renewable energy sources. It also develops models for the efficient generation, use, and conservation of energy. The company was founded on April 28, 1999 and is headquartered in Vienna, Austria.