| Markhus Bolig AS | Kokstad | 2001 |
| Markhus Group AS | Kokstad | 2015 |
| Markhus Holding I AS | Kokstad | 2005 |
| Markhus VVS AS | Sævareid | 2017 |
| Markisespesialisten Asker Og Bærum AS | Asker | 2012 |
| Marko Janke Holding AS | Lyngdal | 2020 |
| Marko Snekkerservice AS | Skaland | 2024 |
| Markon S.C. | 70-65 L Szeczecin | 2014 |
| Markson Tømring AS | Sør-Fron | 2021 |
| Markus Aasen Bygg AS | Grålum | 2026 |
| Markus Hansen AS | Gamle Fredrikstad | 2025 |
| Markus Salen AS | Farsund | 2024 |
| Markus Snekkerservice AS | Brumunddal | 2024 |
| Marlon Holding AS | Sandnes | 2020 |
| Marlun AS | Mjøndalen | 2015 |
| Marma Invest AS | Hordvik | 2023 |
| Marmi Futerno Oü | Ee-74207 Liivamäe | 2024 |
| Marmina AS | Lørenskog | 2022 |
| Marmor Bygg AS | Ulset | 2007 |
| Marnar Bygg AS | Mandal | 1987 |
| Marnar Elektro AS | Mandal | 2021 |
| Maro Bygg AS | Hønefoss | 2017 |
| Marpol Mateusz Szloda | 24-100 Pulawy | 2008 |
| Marschall KG Des Marschall David & Co | It-39057 Balzano | 2021 |
| Marsell Bygg AS | Skjærhalden | 2023 |
| Marsell Invest AS | Skjærhalden | 2023 |
| Marstrand Invest AS | Drøbak | 2008 |
| Marta Ladocha Wiktoria | Pl-59-730 Nowogrodziec | 2025 |
| Marteam. AS | Drøbak | 2013 |
| Marteka Nuf | Lt-96232 Plikiai, Klaipedos Raj. | 2024 |
| Martensen Aps | Dk-9800 Hjørring | 2011 |
| Martex Piotr Wyrkowski | 61-129 Poznan | 2007 |
| Marthinsen & Duvholt AS | Sandefjord | 1998 |
| Marti AS | Oslo | 2011 |
| Marti Tunnel AG Nuf | Ch-3302 Moosseedorf | 2013 |
| Martifer Romania SRL Nuf | Sector 3, 030213 Bucuresti | 2013 |
| Martijn Berk Montage & Onderhoud | 2641 Aj Pijnacker | 2012 |
| Martilobo AS | Oslo | 2022 |
| Martin Appel Service AS | Eidsfoss | 2026 |
| Martin Bang Graving Og Transport AS | Kvelde | 2014 |
| Martin Bekken Strøm AS | Jaren | 2015 |
| Martin Eriksen AS | Sandefjord | 2018 |
| Martin Fix IT AS | Borkenes | 2022 |
| Martin Foss Holding AS | Hafslundsøy | 2019 |
| Martin Fredriksen VVS AS | Sykkylven | 2008 |
| Martin Gläser Montageservice | 08297 Zwönitz | 2011 |
| Martin Hovdum Bygg Og Rehabilitering AS | Yven | 2013 |
| Martin Ivarson AS | Birkeland | 2003 |
| Martin Jarnæs Nilsen AS | Nittedal | 1997 |
| Martin K Holding AS | Lillestrøm | 2024 |
| Martin Lorenz AB | Se-280 22 Vittsjö | 2010 |
| Martin M Bakken AS | Elverum | 1983 |
| Martin Maler AS | Nesodden | 2016 |
| Martin Prestegård AS | Kokstad | 2006 |
| Martin Rønning AS | Heggedal | 2003 |
| Martin Rønning Holding AS | Asker | 2013 |
| Martin Sunnanå AS | Kopervik | 2024 |
| Martin Uggedal AS | Søvik | 1992 |
| Martin Wold Invest AS | Nøtterøy | 2014 |
| Martinez Otero Contract SL | Es-36000 Pontevedra | 2013 |
| Martino Pohlen Tømrer Og Snekkerservice AS | Ulset | 2023 |
| Martins Bygg & Tømrertjenester AS | Flekkefjord | 2020 |
| Martins Eiendom AS | Strømmen | 2018 |
| Martins Elektro AS | Fevik | 2018 |
| Martins Elektroinstallasjon AS | Flateby | 2025 |
| Martins Sokins | Lv-4001 Limbazy Novads | 2014 |
| Martinsen & Sønn Installasjon AS | Fredrikstad | 2009 |
| Martinsen Anlegg AS | Leira I Valdres | 2013 |
| Martinsen Bad & Bolig AS | Oslo | 2016 |
| Martinsen Betong AS | Lundamo | 2012 |
| Martinsen Blikk Og Vedlikehold AS | Sandefjord | 2022 |
| Martinsen Bygg & Eiendom AS | Froland | 2025 |
| Martinsen Bygg (GM) AS | Tofte | 2022 |
| Martinsen Byggtjenster AS | Mehamn | 2022 |
| Martinsen Maling Og Tapet AS | Begna | 2023 |
| Martinsons Träbroar AB | 931 95 Skellefteå | 2010 |
| Martom AS | Mosjøen | 2016 |
| Marum Bygg AS | Olsvik | 2018 |
| Marumsrud Tjenester AS | Atrå | 2018 |
| Maruwa Holding AS | Hafslundsøy | 1999 |
| Marvel Rocks S.L. | Es-28007 Madrid | 2023 |
| Marvid Nilsen AS | Valsøyfjord | 1989 |
| Marvid Nilsen Installasjon AS | Valsøyfjord | 2001 |
| Marvin Hansen Eiendom AS | Sortland | 2014 |
| Marzullo Lavori S.R.L Norge Nuf | Cap 37054 Nogara (Vr) | 2017 |
| Marøy Blikk AS | Bøvågen | 2015 |
| Mas Entreprenør AS | Oslo | 2019 |
| Mas-Stugan AB | Se-792 90 Sollerön | 2012 |
| Masdalen Maskinkompani AS | Søndeled | 1985 |
| Masfjorden Elektro AS | Hosteland | 1982 |
| Masio Vedlikehold & Service AS | Stavanger | 2017 |
| Masito AS | Hundvåg | 1976 |
| Masiv Bygg AS | Klepp Stasjon | 1987 |
| Mask Anlegg AS | Torvastad | 2024 |
| Maskin & Anleggsservice AS | Vadsø | 2006 |
| Maskin & Asfalt AS | Larvik | 2008 |
| Maskin & Eiendom AS | Tromsø | 2013 |
| Maskin & Graveservice AS | Trondheim | 1991 |
| Maskin & Håndverk AS | Revetal | 2025 |
| Maskin & Industriteknikk AS | Gressvik | 2010 |