| Marie Nord AS | Professional & scientific | 2023 |
| Marie Sahba AS | Arts & recreation | 2021 |
| Marie Sofie AS | Wholesale & retail | 2025 |
| Marie Treschow Eiendom AS | Real estate | 2014 |
| Marie Øverby Holding AS | Professional & scientific | 2023 |
| Marieboes Gate 9 AS | Real estate | 2017 |
| Marieboesgt. 16 AS | Real estate | 2006 |
| Mariehh AS | Financial services | 2017 |
| Mariela Invest AS | Professional & scientific | 2025 |
| Marienburg AS | | 2025 |
| Mariendal Eiendom AS | Real estate | 2011 |
| Mariendal Invest AS | | 2026 |
| Marienlunden AS | Real estate | 2011 |
| Marienlyst Barnehage AS | Real estate | 2025 |
| Marienlyst Bolig AS | Real estate | 2025 |
| Marienlyst Bygulv AS | Real estate | 2025 |
| Marienlyst Byutvikling AS | Real estate | 2021 |
| Marienlyst Cafe AS | Hospitality | 2014 |
| Marienlyst Garasjer AS | Transport & logistics | 1957 |
| Marienlyst Holding AS | Real estate | 1984 |
| Marienlyst Legesenter Da | Health & social care | 2013 |
| Marienlyst Næringsbygg AS | Real estate | 2025 |
| Marienlyst Parkeringskjeller AS | Real estate | 2025 |
| Marienlyst Pub AS | Hospitality | 2022 |
| Marienlyst Utvikling AS | Real estate | 2020 |
| Maries Gate 7 B AS | Real estate | 2021 |
| Marihaug Regnskap AS | Professional & scientific | 2014 |
| Mariholtet AS | Hospitality | 2022 |
| Mariia Chernat AS | | 2024 |
| Marikken Og Rikke Harsheim AS | Manufacturing | 2012 |
| Marikollen Torg AS | Real estate | 2020 |
| Marikollåsen AS | Real estate | 2025 |
| Marikove Industrier AS | Real estate | 2005 |
| Maril AS | Financial services | 2005 |
| Marilla AS | Real estate | 2005 |
| Marilyst AS | | 2023 |
| Marimar Invest AS | | 2021 |
| Marimekko Norge, Filial Av Marimekko AB, Sverige Nuf | Wholesale & retail | 2011 |
| Marimetrics AS | Manufacturing | 2020 |
| Marina Group AS | | 2025 |
| Marina Group Midco AS | | 2025 |
| Marina Group Norway AS | | 2025 |
| Marina Group Top Holding AS | | 2025 |
| Marina Group Topco AS | | 2025 |
| Marina Invest AS | | 2024 |
| Marina Malgina AS | Education | 2023 |
| Marinabakken AS | Real estate | 2007 |
| Marinabakken Holding AS | Real estate | 2022 |
| Marine & Railway Services AS | Wholesale & retail | 2014 |
| Marine Capital AS | Financial services | 2005 |
| Marine Development AS | Financial services | 2002 |
| Marine Hill AS | | 2021 |
| Marine Prospects AS | Professional & scientific | 2018 |
| Marine Resources AS | Real estate | 2001 |
| Marine Trading AS | Real estate | 2022 |
| Marine Water Production AS | Professional & scientific | 2019 |
| Marinetech AS | Construction | 2024 |
| Maring Invest AS | | 2024 |
| Marinka Eiendom AS | Real estate | 1998 |
| Marinka Gruppen AS | Wholesale & retail | 1985 |
| Marinosa Grill AS | Hospitality | 2024 |
| Marinspect Norway | | 2025 |
| Mario Tecnoagro Limited | Agriculture & fishing | 2019 |
| Marion Iwe Thorsteinsen Holding AS | | 2025 |
| Maris Stella AS | Information & communication | 2019 |
| Marisan AS | Professional & scientific | 2022 |
| Marise Invest AS | | 2026 |
| Mariss Holding AS | Real estate | 2004 |
| Marit Crawfurd Holding AS | Financial services | 2013 |
| Marit Dahlsrud AS | Real estate | 1991 |
| Marit Garberg Andvig AS | Health & social care | 2015 |
| Marit Larsen AS | Arts & recreation | 2010 |
| Marit Røste Produksjoner SA | Arts & recreation | 2019 |
| Marita Drift AS | Health & social care | 1995 |
| Maritel AS | | 1999 |
| Maritim Fastfood AS | Hospitality | 1994 |
| Maritime & Merchant Bank ASA | Financial services | 2013 |
| Maritime Analytics AS | Professional & scientific | 2012 |
| Maritime Asset Partners AS | | 2019 |
| Maritime Innovation Bru AS | Information & communication | 2026 |
| Maritime Links AS | Professional & scientific | 2018 |
| Maritime Opportunities AS | Financial services | 2012 |
| Maritime Optima AS | Information & communication | 2018 |
| Maritime Truck AS | Transport & logistics | 1968 |
| Maritime Yield Company AS | Transport & logistics | 2021 |
| Maritimt Hus AS | Real estate | 2003 |
| Maritoppen Invest AS | Financial services | 2005 |
| Marius Borge Lyd AS | Arts & recreation | 2016 |
| Marius Bygg Service AS | Construction | 2022 |
| Marius Dudek AS | Construction | 2021 |
| Marius Entreprenør AS | Administrative & support | 2025 |
| Marius Granly AS | Wholesale & retail | 2018 |
| Marius Gruzdys | Construction | 2005 |
| Marius Gulliksen Holding AS | | 2025 |
| Marius Gundersen Holding AS | | 2024 |
| Marius I. M. Holding AS | | 2026 |
| Marius Johansen Hansen AS | Manufacturing | 2024 |
| Marius Listerud AS | Professional & scientific | 2010 |
| Marius Müller Minde AS | Information & communication | 2013 |
| Marius Nielsen Holding AS | Information & communication | 2019 |