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| Industriverktøy AS | Leksvik | 2011 |
| Industry Facility Installation Services Sp.Z.O.O. Nuf | Pl-00-676 Warszawa | 2025 |
| Ineo Reseaux Haute Tension | 69100 Villeurbanne | 2014 |
| Ineos Bamble AS | Stathelle | 1993 |
| Ineos Enterprises Norway Holdings AS | Tyssedal | 2023 |
| Ineos Manufacturing Belgium | Be-2040 Antwerpen | 2023 |
| Ineos Rafnes AS | Stathelle | 2000 |
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| Inesse Jewelry AS | Sandnes | 2017 |
| Inetutta AS | Sandnes | 2025 |
| Infentec Fabrication AS | Søfteland | 2024 |
| Inference AS | Oslo | 2000 |
| Inference Invest AS | Grua | 2005 |
| Inferrum AS | Brumunddal | 2023 |
| Infi Service AS | Roverud | 2023 |
| Infigi AS | Oslo | 2013 |
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| Informantene Ans | Stavanger | 1992 |
| Infotek AS | Folldal | 1987 |
| Infrabeam AS | Oslo | 2016 |
| Inframarin AS | Stryn | 2024 |
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| Ingelsrud Konditori AS | Magnor | 2017 |
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| Ingenjörsfirma Evert Johansson AB | Se-543 51 Tibro | 2020 |
| Ingenjörsfirma G. Hedlund Aktiebolag Nuf | Se-822 30 Alfta | 2025 |
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| Ingvaldsen AS | Brumunddal | 2018 |
| Ingvaldsen Mekaniske AS | Brumunddal | 2018 |
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| Innherredsbakeriet AS | Verdal | 2001 |
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| Innlandet Elementfabrikk AS | Ilseng | 2017 |
| Innlandet Fjøsteknikk AS | Moelv | 2025 |
| Innlandet Hydraulikk Og Service AS | Kolbu | 2024 |
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| Innlandet Industriservice AS | Gjesåsen | 2024 |
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| Innlandet Mekaniske AS | Furnes | 2020 |
| Innlandet Precut & Takstol AS | Næroset | 2018 |
| Innlandet Sveis Og Hydraulikk AS | Dokka | 2013 |
| Innlandet Verkstedservice AS | Sagstua | 2023 |
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| Innofiber AS | Fredrikstad | 2021 |
| Innofiber Holding AS | Fredrikstad | 2022 |
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| Innovagruppen AS | Ringebu | 2020 |
| Innovasjø Marine Systems Norway AS | Bergen | 2018 |
| Innovation & Design Technology AS | Steinkjer | 2015 |
| Innovation Nilu AS | Kjeller | 1996 |
| Innovatrykk AS | Hosle | 2023 |
| Innovolve AS | Oslo | 2024 |
| Innowo AS | Oslo | 2019 |
| Innowo Holding AS | Oslo | 2012 |
| Innramming AS | Kristiansand S | 2022 |
| Innredningssnekkeriet Ans | Løten | 1995 |
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| Inntre Kjeldstad AS | Steinkjer | 2003 |
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| Inocon Industrial Plants GmbH | 4800 Attnang-Pucheim | 2015 |
| Inovyn Norge AS | Stathelle | 2000 |
| Inox Instal Spolka Z Ograniczona Odpowiedzialnoscia Spolka Komandytowa | Pl-32-800 Brzesko | 2018 |
| Inox Service S.R.L. | It-Cap 97016 Pozzallo | 2017 |