| Marinegruppen AS | Tysnes | 2025 |
| Marinemekanisk AS | Torvastad | 2021 |
| Marinepartner AS | Våler I Østfold | 2015 |
| Marineservice Holmen Yachtværft AS | Nesbru | 2024 |
| Marineservice Oslo AS | Nittedal | 2021 |
| MARINESERVICE1 AS | Rygge | 2012 |
| Marineshaft | Dk-9850 Hirtshals | 2019 |
| Marinpet AS | Stavanger | 1999 |
| Marintech Invest AS | Tveit | 2018 |
| Mario Ristic | Cz-664 84 Stanoviste | 2025 |
| Marisafe Sp.Z.O.O | Pl-70-651 Szczecin | 2011 |
| Maritim Motor AS | Tomrefjord | 2011 |
| Maritim Power AS | Abelvær | 2020 |
| Maritim Power AS | Abelvær | 2026 |
| Maritim Sveiseservice AS | Tromsø | 2016 |
| Maritim Sveiseservice Eiendom AS | Tromsø | 2016 |
| Maritim Sveiseservice Holding AS | Tromsø | 2016 |
| Maritim Varme AS | Vear | 2019 |
| Maritime Construction Solutions AS | Laksevåg | 2007 |
| Maritime Elektrisk | Mandal | 1985 |
| Maritime Engineering | 5964 Marstal | 2014 |
| Maritime Holding AS | Vestnes | 2005 |
| Maritime Innredning Nord AS | Grovfjord | 2014 |
| Maritime Montering Norway AS | Bygstad | 1993 |
| Maritime Montering Poland SP Z O.O. Nuf | 80-958 Gdansk | 2007 |
| Maritime Montering Romania S.R.L Nuf | Ro-800048 Galati | 2026 |
| Maritime Partner AS | Ålesund | 1994 |
| Maritime Protection AS | Kristiansand S | 2009 |
| Maritime Rig Service AS | Grimstad | 2016 |
| Maritime Services Eood | 9005 Varna | 2018 |
| Maritime Supply Ans | Stavanger | 1991 |
| Maritimt Kompani AS | Ranheim | 2009 |
| Maritronic & Kristiansand Båtservice AS | Kristiansand S | 2007 |
| Marius Hognestad Motorsport AS | Nærbø | 2014 |
| Marius Johansen Hansen AS | Oslo | 2024 |
| Marius Knudsen AS | Kristiansand S | 2021 |
| Marius Morel France SAS Nuf | Fr-39400 Morbier | 2018 |
| Marius Stamnes Boktrykkeri AS | Oslo | 1965 |
| Mark & Grøde AS | Kragerø | 2015 |
| Markajentene AS | Oslo | 2012 |
| Markanes Maskinservice AS | Snillfjord | 2021 |
| Markebo Industribygg AS | Åsgårdstrand | 1985 |
| Markisehaco AS | Lundamo | 2016 |
| Markkus Industrisvets & Montage | 461 33 Trollhättan | 2004 |
| Markmaster AS | Karmsund | 1998 |
| Markos Båtservice AS | Råde | 2020 |
| Markus Andreas Waligorski | 44379 Dortmund | 2007 |
| Markus Wehrle | 93081 Vglommersträsk | 2009 |
| Marlins Møbelverksted AS | Nordby | 2021 |
| Marlobobos AS | Sande I Vestfold | 2019 |
| Marmor AS | Holmestrand | 2013 |
| Marna Motor AS | Mandal | 1989 |
| Marnar Bruk AS | Marnardal | 1991 |
| Marnar Maskinservice AS | Mandal | 2024 |
| Marsipan Compagniet AS | Oslo | 2016 |
| Marstein Seaweed AS | Storebø | 2016 |
| Marstia AB Nuf | 852 36 Sundsvall | 2024 |
| Martas Cafe AS | Heggedal | 2025 |
| Marte Linga - Sko Og Saum AS | Norheimsund | 2023 |
| Martech Marine AS | Bremnes | 2020 |
| Martha's Fancy Kaker Og Uten Gluten AS | Flaktveit | 2026 |
| Marthas Delikatesser AS | Kolltveit | 1996 |
| Marthe Elise AS | Tomasjord | 2025 |
| Martin E Birknes Eftf AS | Byrknesøy | 1991 |
| Martin Feldmann Tannteknikk AS | Stavanger | 2010 |
| Martin Kalager Drift AS | Holmestrand | 2005 |
| Martin Sveis Og Mekaniske AS | Gardvik | 2015 |
| Martin Utvikling AS | Mandal | 2005 |
| Martin Walderhaug Eftf AS | Ålesund | 2000 |
| Martins Maskinservice AS | Vikersund | 2012 |
| Martins Motorservice AS | Flekkefjord | 2012 |
| Martins Møbler Og Montasje AS | Ål | 2020 |
| Martspaw AS | Drammen | 2025 |
| Marumen AS | Skien | 2016 |
| Marveous | Hafrsfjord | 2018 |
| Marvold AS | Rørvik | 2020 |
| Marzipan Design Da | Stavern | 2010 |
| Mas Aero AS | Gardermoen | 2025 |
| Masaga AS | Ålesund | 2022 |
| Mascot Høie AS | Brekstad | 1996 |
| Masertek AS | Gjerdrum | 2023 |
| Mash AS | Bjørndalstræ | 2024 |
| Maskeraden Strikkeri Da | Skedsmokorset | 1989 |
| Maskin Mekano | Se-550 09 Jönköping | 2021 |
| Maskin Og Eiendom Invest AS | Grimstad | 2002 |
| Maskin Og Industriservice AS | Andebu | 2022 |
| Maskin Og Teknikk AS | Bodø | 2024 |
| Maskin Og Truckservice AS | Stokke | 2019 |
| Maskin Reparasjon Stjørdal AS | Stjørdal | 2018 |
| Maskin Service Nord AS | Alta | 2024 |
| Maskin Support AS | Alta | 2026 |
| Maskin-Elektrisk AS | Drammen | 1970 |
| Maskin-Service AS | Kleppstad | 2021 |
| Maskindeler AS | Bud | 1983 |
| Maskinering AS | Ski | 1978 |
| Maskinering AS | Bodø | 2002 |
| Maskinfabrikken Hamebo | Dk-9300 Sæby | 2016 |
| Maskinfabrikken Hillerslev | Dk-7700 Thisted | 2010 |
| Maskinia Holding AS | Porsgrunn | 2008 |
| Maskinpakking AS | Åros | 2002 |