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| Kanfa AS | Lysaker | 2001 |
| Kanfer Shipping Management AS | Nøtterøy | 2017 |
| Kankerud Fjelltak AS | Svingvoll | 2007 |
| Kappa Training and Consulting Ltd | Surrey R42 75L | 2007 |
| Kar Digital Limited Nuf | Tananger | 2026 |
| Karl Egil Klevstadlien Offshore AS | Torp | 2017 |
| Karpinsky Oil & Gas Company AS | Oslo | 1997 |
| Kca Deutag Drilling GmbH | 48455 Bad Bentheim | 2007 |
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| Kimberlitt AS | Oslo | 2008 |
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| Kingsrose Finnmark AS | Karasjok | 2023 |
| Kinna AS | Hjellestad | 2016 |
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| Kistos Energy (Norway) AS | Lysaker | 2017 |
| KJ Lifting Services Ltd | Newcastle Ne27 0Fq | 2020 |
| Kjel Og Brennerservice AS | Garnes | 2018 |
| Kjell Stuvik Holding AS | Vormedal | 2018 |
| Kjennskogen Drift AS | Porsgrunn | 2018 |
| KL Grus AS | Selbu | 2011 |
| Kleppen Massetak AS | Mosjøen | 2017 |
| Kmnor AS | Jørpeland | 2017 |
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| Kongslien Petrophysics AS | Hundvåg | 2017 |
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| Kraftentreprenøren AS | Sogndal | 2014 |
| Kragerø Naturstein AS | Risør | 2005 |
| Kragset Alt Mulig AS | Åram | 2025 |
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| Kvernvold Invest AS | Stavanger | 2008 |
| Kvestad Massemottak AS | Ås | 2020 |
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| Langnes Marmorbrudd AS | Eide | 2021 |
| Langnes Marmorbrudd Holding AS | Eide | 2021 |
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| Larvik Granite Pukk AS | Larvik | 2021 |
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| Lefdal Well Consultants AS | Stavanger | 2004 |
| Legacy in Stone AS | Lier | 2024 |
| Leite Pukk AS | Skodje | 2013 |
| Lemax Inspections Limited Nuf | Dl5 4Sr Durham | 2015 |
| Lensvik Pukkverk AS | Lensvik | 2017 |
| Lepsoy Offshore Nuf | Lepsøy | 2018 |
| Liahona Agency Ltd | Cornwall Pl15 9Sd | 2015 |
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| Lime Petroleum Holding AS | Oslo | 2024 |
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| Lindland Performance AS | Lyngdal | 2014 |
| Lindland Pukk AS | Lyngdal | 2004 |
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| Liskifer AS | Sørli | 1990 |
| Lofotpukk AS | Bøstad | 2007 |
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