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| Carbon Consulting AS | Oslo | 2021 |
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| Carbon Mover AS | Hafrsfjord | 2025 |
| Carbon Reduction AS | Oslo | 2014 |
| Carbon Reduction Technologies AS | Bodø | 2008 |
| Carbon Solutions AS | Vinterbro | 2012 |
| Carbon Twelve AS | Asker | 2021 |
| CARBON14 AS | Haugesund | 2007 |
| Carbonor AS | Kristiansand S | 2021 |
| Carcarebag AS | Nesttun | 2022 |
| Cardea Eiendom AS | Høvåg | 2006 |
| Cardhu Invest AS | Tranby | 2023 |
| Cardiaccs AS | Oslo | 2009 |
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| Cardinal Consult AS | Ringebu | 2009 |
| Cardinor AS | Oslo | 2015 |
| Cardo 8614 AS | Bergen | 1972 |
| Cardo Partners AS | Oslo | 2000 |
| Care and Create AS | Oslo | 2025 |
| Care Bioscience AS | Hosle | 2026 |
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| Care IT AS | Lysaker | 2020 |
| Careen AS | Lier | 2015 |
| Careless AS | Kristiansand S | 2022 |
| Carepacks AS | Vinterbro | 2016 |
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| Carfreaks Media AS | Hamar | 2023 |
| Cargo Trine Consulting AS | Gjerdrum | 2020 |
| Cargo-Man AS | Hundvåg | 2016 |
| Cargoit Norge | Se-194 34 Upplands Väsby | 2018 |
| Cargoland Logistics Nuf | Lt-06245 Vilnius | 2018 |
| Cargomaster AS | Kleppestø | 2017 |
| Cariro AS | Kvaløya | 2017 |
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| Carjam Consulting AS | Levanger | 2012 |
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| Carl Källqvist IT & Industriservice AB | Se 534 94 Vara | 2021 |
| Carl Og Roar Naturundersøkelser AS | Ridabu | 2012 |
| Carl Peder Consult AS | Oslo | 1990 |
| Carl Sebastian Smedberg Holding AS | Oslo | 2021 |
| Carlab Paint Da | Gardermoen | 2024 |
| Carlberghome Styling AS | Moss | 2019 |
| Carleniusai AS | Trondheim | 2026 |
| Carlo Caso Invest AS | Stavanger | 2023 |
| Carlos Bernardo Cervo Ans | Oslo | 2003 |
| Carlotto DK | Dk-8220 Brabrand | 2005 |
| Carlsen & Carlsen AS | Sandnes | 2026 |
| Carlsen Services AS | Tjodalyng | 2016 |
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| Carlsson Design AS | Svelvik | 2016 |
| Carlsson Lewis Services AS | Tofte | 2025 |
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| Carlton Street Partners AS | Haslum | 2021 |
| Carlzent AS | Drammen | 2023 |
| Carmar AS | Tananger | 2006 |
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| Carnetic AS | Sola | 2022 |
| Carnetic Norway AS | Sola | 2023 |
| Carnival Group Norway | It-16121 Genova | 2018 |
| Carnot Efficient Energy AS | Oslo | 2016 |
| Caro Capital AS | Morvik | 2020 |
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| Caroliussen Eftf. AS | Risøyhamn | 2016 |
| Carpa AS | Lommedalen | 2000 |
| Carpatia Holding AS | Hafrsfjord | 2004 |
| Carpatia Strategy AS | Haugesund | 2026 |
| Carpe Diem Consulting AS | Oslo | 2023 |
| Carpe Diem Partners AS | Oslo | 2015 |
| Carpe Fortuna AS | Oslo | 2013 |
| Carrentalno Da | Stabekk | 2000 |
| Carrera Solution Nuf | Oslo | 2014 |
| Carrick Oil Services Ltd | Peterhead Ab42 3Fl Scotland | 2020 |
| Carrier Solutions UK Ltd. Nuf | Pl67Db Plymouth, Devon | 2026 |
| Carrodano AS | Stavanger | 2025 |
| Carry on AS | Molde | 2025 |
| Carsmart AB Nuf | Se-191 81 Sollentuna | 2025 |
| Carspaze Nordic AS | Oslo | 2010 |
| Carsten Søreide AS | Rådal | 2014 |
| Carsten Søreide Consulting Da | Rådal | 2009 |
| Carsten Søreide Regnskap AS | Rådal | 2024 |
| Carstens Invest AS | Trondheim | 2020 |
| Cartar Management AS | Oslo | 2003 |
| Carterra LLC | 77079 Houston Texas | 2017 |
| Cartesian AS | Trondheim | 2023 |
| Carthe AS | Dale I Sunnfjord | 2010 |
| Carthea AS | Bergen | 2007 |
| Cartogravie AS | Oslo | 2022 |
| Cas Konsult Og Eiendom AS | Stabekk | 2006 |
| Casa Canarios AS | Oslo | 2013 |