Alle Firmen mit dem Anfangsbuchstaben I
- Ing. Rieder InstallationsgesmbH
- Ing. Rieder Marco
- Ing. Rieder Stefan Alexander
- Ing. Riedl Michael
- Ing. Riedler Richard
- Ing. Rieger Georg Heinrich
- Ing. Riegler Christian Josef Herbert
- Ing. Riegler Johann Günter
- Ing. Riegler Jürgen
- Ing. Rienessl Thomas Peter
- Ing. Riepl Irmtraud
- Ing. Riesemann GmbH
- Ing. Riesenhuber Karl
- Ing. Rigger Christoph Maximilian
- Ing. Rimpler Claus
- Ing. Ringerthaler Albert Franz
- Ing. Ringhofer Stefan Albert Klaus
- Ing. Ringseis Georg
- Ing. Rinner Patrick R.
- Ing. Rinößl Christian
- Ing. Rist Michael
- Ing. Ritter Gerhard
- Ing. Rizvic Kenan
- Ing. Robatsch Werner
- Ing. Robert Augeneder GmbH
- Ing. Robert Kutschera Bau
- Ing. Robert Schunker - Daten- und Medientechnik
- Ing. Robert Trenkwalder - Ingenieurbüro für Maschinenbau
- Ing. Robert Winkler GmbH
- Ing. Rohm Gregor
- Ing. Rohrbacher Bianca
- Ing. Rohrweck Florian
- Ing. Roiser Christoph Johann
- Ing. Roland Kretschmer Baumeister u Zimmermeister GmbH
- Ing. Roland Pickl e.U.
- Ing. Roland Wiplinger GmbH
- Ing. Roman Aböck e.U.
- Ing. Roman Buchta e.U.
- Ing. Roman Gottschlich - Stahlhandel
- Ing. Roman Koselsky e.U.
- Ing. Roman Strolz | Möbel- und Innenausbau
- Ing. Rommer Peter
- Ing. Romski Edward
- Ing. Rosenauer Peter Andreas
- Ing. Rosenbaum Wolfgang Erich
- Ing. Rosenkranz Manuel Rudolf
- Ing. Rosian Meinrad
- Ing. Rossmanith Christopher Benjamin
- Ing. Rossmüller Gerald Frank
- Ing. Rosteck Wolfgang
- Ing. Roth Franz
- Ing. Roth Werner Bruno
- Ing. Rothbart Frank
- Ing. Rotheneder Thomas
- Ing. Rubin Christian Andreas
- Ing. Ruckhofer Gregor
- Ing. Rudlstorfer Dieter
- Ing. Rudoba Dietram
- Ing. Rudolf Baier e.U.
- Ing. Rudolf Ehrengruber
- Ing. Rudolf Kaiser Beteiligungsgesellschaft m.b.H.
- Ing. Rudolf Mayer Elektrotechnik GmbH
- Ing. Rudolf Pfaffenlehner GmbH
- Ing. Rudolf Rastl e.U.
- Ing. Rudolf Schall - Elektrotechnik
- Ing. Ruggenthaler Ronald
- Ing. Rulitz Dieter
- Ing. Rummel Gesellschaft m.b.H.
- Ing. Rumpelmayr Stefanie
- Ing. Rumpf Florian Herbert
- Ing. Rupert Klausbauer Beteiligungs GmbH
- Ing. Rupert Schmied KG
- Ing. Rupert Weber e.U.
- Ing. Ruthardt Herwig
- Ing. Ruttmann Franz
- Ing. Ruzicka Walter
- Ing. Röck GmbH
- Ing. Rögelsperger & Co. GMBH (RÖCO)
- Ing. Rögner Hannes
- Ing. Römer Rene