Bedrift O - Fornebu
- Otee AS
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- OBOS BBL
- Omnipartner AS
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- Overå Mgmt
- Oslo Uteliv AS
- Opheim Torbjørn
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- Oxen Eiendom AS
- Oksenøya Båtutstyr AS
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- Ocean Sun AS
- Oksenøya Marina AS
- Olsen Thomas
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- Oksenøya sykehjem
- Organos Norway
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- Organos Norway
- Omar Al-Zobeidy
- OBOS BBL Avd Fornebulandet
- Opis Eiendom AS
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- OBOS Koksa AS
- Oslo Bedriftsrådgivning AS
- Optical Storage AS
- Oflow Group AS
- Ocg Holding AS
- Oslofjorden Dykkesenter AS
- Oksen Idrettslag
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- Oslo Uteliv Drift AS
- Oslo Uteliv Catering AS
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- Oksenøya Skole Fau
- Otterstad 2.0
- Ole Henrik Saxegaard
- Oddvin Søgnesand Tømrerfirma
- Oslo Fasadeservice Limited
- Odd Arne Tjersland
- Ortoped Erik Bjørbæk
- Oksenøya Skole Fau
- Ole Norli Småtjenester IT Enk
- Oksenøya Bryggesamvirke 1 SA
- Offshore Charter Frode Hope