| Mar-Sec AS | Moss | 2017 |
| Maravelakis Holding AS | Frogner | 2024 |
| Mareco AS | Stavanger | 2018 |
| Mareka AS | Hamarvik | 2003 |
| Marexcon Limited | Nr349Aj Suffolk | 2012 |
| Mari Company AS | Skedsmokorset | 2017 |
| Mari Fjøsne Holding AS | Drammen | 2023 |
| Marianas Ltd | East Yorkshire Yo16 4Jb | 2007 |
| Mariann Gramstad AS | Kvernaland | 2026 |
| Marianne a. Lervik AS | Drammen | 2020 |
| Marianne Tours AS | Åfjord | 2012 |
| Marida Hydrographic Limited | Bognor Regis Po21 2Se England | 2019 |
| Marielunden Services AS | Stavanger | 2014 |
| Marieroholding AS | Stavanger | 2015 |
| Marin Odysse AS | Trondheim | 2004 |
| Marindock Ltd | Mahe | 2007 |
| Marine & Industri Power Midt-Norge AS | Trondheim | 2018 |
| Marine Computation Services Kenny SAS | 75002 Paris | 2012 |
| Marine Crew & Estate AS | Stokmarknes | 2025 |
| Marine Enterprise Solutions AS | Trondheim | 2021 |
| Marine Geophysical Survey Inc | Us-70583-5400 Scott, La | 2014 |
| Marine Harvest (Scotland) Limited | Ky11 2Yw Rosyth, Fife, Scotland | 2013 |
| Marine Installasjon AS | Sandefjord | 2003 |
| Marine Isolering AS | Bekkjarvik | 2010 |
| Marine Manning Service Ltd | 81-342 Gdynia | 2005 |
| Marine Nord AS | Kirkenes | 2003 |
| Marine Seven AS | Os | 2004 |
| Marinespace Ltd | Gb - So14 3Jz Southampton | 2014 |
| Mariteam AS | Trondheim | 2000 |
| Maritim AS | Arendal | 2000 |
| Maritim Bemanning AS | Måløy | 2008 |
| Maritim Facilitator Norway AS | Vadsø | 2018 |
| Maritim Utleige AS | Laksevåg | 2024 |
| Maritime Consulting AS | Elnesvågen | 2012 |
| Maritime Services AS | Atløy | 2012 |
| Maritimeservice AS | Langevåg | 2020 |
| Marius Entreprenør AS | Oslo | 2025 |
| Marius O Eiendom AS | Sandefjord | 2012 |
| Marius O Holding AS | Sandefjord | 2012 |
| Marius of Norway AS | Oslo | 2013 |
| Marjon AS | Flisa | 2018 |
| Mark Hall Engineering Ltd | Middlesbrough Cleveland Ts1 3Qw | 2020 |
| Marka AS | Fagerstrand | 2020 |
| Markalabben AS | Hokksund | 2023 |
| Markeder Og Messer AS | Sørum | 2026 |
| Markeds Invest AS | Haugesund | 1974 |
| Marker Maskin Og Utleie AS | Ørje | 2020 |
| Marketform Management Services Limited | London Ec3V Obg | 2015 |
| Markmanager Inc | Willington Delaware | 2008 |
| Markmonitor (Aii-D) Inc | Id 83642 | 2022 |
| Markmonitor Corporate Services Inc | Wilmington Delaware | 2007 |
| Markmonitor EU Registrations Inc. | Idaho 83642 | 2021 |
| Marksman Technicians Limited | Aberdeenshire Ab42 5Hn | 2012 |
| Markus Sebastian Gossner Nuf | De-88471 Laupheim | 2024 |
| Markveien Drueklubb Da | Oslo | 2024 |
| Marlin Green Ltd | London Ec1V 3Ps | 2013 |
| Marlin Yachting Ltd | Isle Of Man Im99 4Pd | 2026 |
| Marmimax Da | Stadsbygd | 2000 |
| Marnet AS | Gressvik | 2017 |
| Maro Technology Limited | Wanchai | 2019 |
| Marok Stillas AS | Nykirke | 2026 |
| Marpos AS | Nærsnes | 1998 |
| Marrent AS | Fenstad | 2024 |
| Marshall Norway AS | Oslo | 2012 |
| Mart SP. Z O.O. Spolka Komandytowa | Pl-80-351 Gdansk | 2012 |
| Marta Mrozkiewicz Martuska | 80-103 Gdansk | 2006 |
| Marthe Carrara AS | Austmarka | 2015 |
| Marti GmbH | De-70567 Stuttgart | 2013 |
| Martin Blom AS | Rong | 2005 |
| Martin Fidem AS | Oslo | 2002 |
| Martin Frank International B.V. | Wassenaar 2243Cr | 2015 |
| Martin Igancio Irastorza | 1414 Capital Federal Buenos Aires | 2012 |
| Martin J. Holter AS | Vesterøy | 2008 |
| Martin Killingmo AS | Slattum | 2017 |
| Martin Langseth AS | Nes På Hedmarken | 2016 |
| Martin Offshore Ltd | Moray Iv30 Ije | 2018 |
| Martin Røe Holding AS | Oslo | 2021 |
| Martinsen Aviation AS | Holmestrand | 2019 |
| Martinsen Renhold & Vedlikeholdstjenester AS | Notodden | 2021 |
| Martinshus AS | Arendal | 2011 |
| Martracon Crewmanagement Limited | Cy-3100 Ayios Nicolaos, Limassol | 2022 |
| Martracon Shipmanagement Norway AS | Stavanger | 2021 |
| Marubeni Corporation | 100-8088 Tokyo | 2013 |
| Marubeni-Itochu Tubulars Europe PLC | London Ec4A 2Ew England | 1999 |
| Marum Executive Search AS | Nesøya | 2006 |
| Maruwa Anlegg & Eiendom AS | Hafslundsøy | 2006 |
| Marvella Majad Oü | 68301 Sooru | 2005 |
| Marwil Carbon AS | Drammen | 2021 |
| Marwil Holding AS | Nes På Hedmarken | 2022 |
| Mary Jannes Renholdsservice AS | Sunde I Sunnhordland | 2020 |
| Marø Havbruk Eigedom AS | Svanøybukt | 1996 |
| Masa Stadsvik Da | Dolmøy | 2024 |
| Maskin & Transport Da | Kristiansand S | 1999 |
| Maskin AS Sterling | Oslo | 1940 |
| Maskin Konsulenten AS | Jessheim | 2019 |
| Maskin Og Eiendom AS | Melsomvik | 2025 |
| Maskin Og Fritid Grytbakk AS | Tydal | 2018 |
| Maskin Og Produksjon AS | Morgedal | 2022 |
| Maskin Og Utemiljø AS | Mysen | 2005 |
| Maskin Og Utleie AS | Tiller | 2024 |