| Mar Celi Jaloszynski | 87-812 Wloclawek | 2008 |
| Mar-Bud | Etne | 2006 |
| Marand AS | Heggedal | 2023 |
| Maras Steinkjer AS | Steinkjer | 2014 |
| Marat Burkhanshin AS | Sortland | 2021 |
| Marba AS | Narvik | 2026 |
| Marbre AS | Årnes | 2006 |
| Marbre Eiendom AS | Årnes | 2003 |
| Marbre Elektro AS | Vormsund | 2008 |
| Marbud AS | Sandvika | 2015 |
| Marbud Marianne Kozlowska | 26-600 Radom | 2008 |
| Marbudhouse Marek Durlik | Pl- 6-120 Blizyn | 2014 |
| Marcar AS | Elverum | 2016 |
| Marcel Bygg Og Renhold AS | Lørenskog | 2023 |
| Marcin Bany's Techmb | 41-260 Slawkow | 2011 |
| Marcin Kardas Deffor | Pl21-411 Wolka Domaszewska | 2025 |
| Marcin Pawlowski | Molde | 2007 |
| Marcin Taukin Nuf | 71-017 Szczecin | 2014 |
| Marco Ltd Spolka Z Ograniczona Odpowiedzialnoscia | 02-626 Warzava | 2005 |
| Marco Technology KFT Nuf | 2905 Th Capelle Aan Den Ijssel | 2008 |
| Marcom AS | Laksevåg | 2025 |
| Marcus - Handverker AS | Skui | 2020 |
| Marcus Holding AS | Skien | 2025 |
| Marcus Högberg Rail AB Nuf | Se-664 95 Borgvik | 2025 |
| Marcusson & Jönrup Entreprenad AB | Se - 432 32 Varberg | 2014 |
| Mardahl Invest AS | Orkanger | 2023 |
| Mardal Elektro AS | Haugesund | 2026 |
| Mardal Rør AS | Sandane | 1999 |
| Mareby Bygg Og Anlegg AS | Brattvåg | 2019 |
| Marek Marcinkowski Uslugi Budowlane | 83-221 Osiek | 2006 |
| Marek Modzelewcki | Grålum | 2007 |
| Marek Sosnowski | 43-600 Jaworzno | 2007 |
| Marek Wierzchowski Champion Nail | Pl-04083 Warszawa | 2016 |
| Marelarn Oü | Sauga Vald 85008 | 2007 |
| Maremi Invest AS | Sandefjord | 2007 |
| Marestonia | Ee-110119 Tallinn Harjumaa | 2020 |
| Marger 2000 KFT | Oslo | 2011 |
| Margo- Wojchiech Kilijan | Høvik | 2004 |
| Mari Access Solution AS | Drammen | 2021 |
| Marian Jelinski | 84-200 Wejherowo | 2007 |
| Marian Kowalski Marys | Grålum | 2007 |
| Marianne Gjerde AS | Innfjorden | 2005 |
| Mariestads Bygg & Fastighetsservice AB | 542 73 Mariestad | 1997 |
| Marimatic AS | Fornebu | 2014 |
| Marina Solutions AS | Eidsnes | 2010 |
| Marine & Home Interiors AS | Tomrefjord | 2026 |
| Marine Bygg AS | Torvastad | 2025 |
| Marine Electrical Installations Ltd | Kirkintilloch G66 1Xf | 2016 |
| Marine Eltech AS | Skånevik | 2012 |
| Marine Tech AS | Lillestrøm | 2003 |
| Marinel Nuf | Stord | 2015 |
| Marinetech AS | Oslo | 2024 |
| Marini S.P.A. Nuf | It-48011 Alfonsine | 2023 |
| Marinoni Spa | It-16152 Genova | 2018 |
| Mario Bygg AS | Siggerud | 2015 |
| Mario F Bygg AS | Fiskarstrand | 2026 |
| Mario's Heletre AS | Ræge | 2026 |
| Marion S.C.M. Malinowski, S.Wojtkowski Nuf | Pl-18-300 Zambrow | 2012 |
| Marios Riving & Flis AS | Auli | 2018 |
| Maripav Limited | Dn15 6Lj Scunthorpe | 2006 |
| Maristugu AS | Vågå | 2019 |
| Maritex Marine AS | Orre | 2016 |
| Maritex Rental AS | Orre | 1997 |
| Maritim Elektronikk Asker & Bærum AS | Billingstad | 2022 |
| Maritim Elektroservice AS | Tromsø | 2021 |
| Maritim Innredning AS | Lesund | 2023 |
| Maritim Montering AS | Barkåker | 2021 |
| Maritim-Elektro AS | Klæbu | 2018 |
| Maritime Energy Service AS | Stavanger | 2017 |
| Maritime Polarwood AS | Ålesund | 2006 |
| Marium Group Nuf | Ee-10917 Tallinn | 2019 |
| Marius Bygg AS | Sandvika | 2017 |
| Marius Bygg Service AS | Oslo | 2022 |
| Marius Byggservice AS | Bergen | 2026 |
| Marius Dudek AS | Oslo | 2021 |
| Marius Engelund AS | Fall | 2020 |
| Marius Fevang AS | Torød | 2013 |
| Marius Gruzdys | Oslo | 2005 |
| Marius Interiør AS | Arendal | 2020 |
| Marius Maler Service AS | Båstad | 2017 |
| Marius Micula AS | Larvik | 2023 |
| Marius Opedal | Hovland | 2013 |
| Marius Renovering AS | Heimdal | 2020 |
| Marius Snekker Og Vedlikehold AS | Strømmen | 2015 |
| Marius Snekker Service AS | Askim | 2012 |
| Marius Teigland AS | Os | 2025 |
| Marius VVS AS | Oslo | 2025 |
| Marius Waale AS | Helgeroa | 2021 |
| Mariusskivenes AS | Ridabu | 2023 |
| Mariusz Kozinski | Lørenskog | 2011 |
| Mariusz Krekora Bud Mar | Kragerø | 2007 |
| Mariusz Snekkerservice AS | Vardø | 2019 |
| Mariusz Tamiola Usl Remontowe | 81-649 Gdynia | 2006 |
| Markan El AS | Karasjok | 2018 |
| Markant AB Nuf | Se-86295 Njurunda | 2022 |
| Markegård Bygg AS | Hemsedal | 2022 |
| Markegård Bygg Da | Hemsedal | 2013 |
| Markegård Mur & Flis AS | Hemsedal | 2022 |
| Marker Anlegg AS | Ørje | 2009 |
| Marker El-Installasjon AS | Ørje | 2018 |