This directory aims at historical review only and does not claim to provide actual information.
| Company Name | Address | Postcode | Place | Awarded on | Type of award |
| Oswald Schuhfabrik GesmbH | | 4881 | Straß im Attergau | 10.02.1984 | revocable |
| Oberösterreich - Touristik - Gesellschaft m.b.H. | Freistädter Str. 119 | 4041 | Linz | 13.06.2007 | revocable |
| Österreichische Brau AG | Lustenau 54 | 4020 | Linz | 15.10.1971 | revocable |
| Ochsner & Sohn GesmbH & Co KG | Oberfeldstraße 8 | 4020 | Linz | 27.05.1980 | revocable |
| Österreichische Stickstoffwerke AG | St.Peter 224 | 4020 | Linz | 15.07.1964 | revocable |
| Company Name | Address | Postcode | Place | Awarded on | Type of award |
