| Marius of Norway AS | Administrative & support | 2013 |
| Marius Paulsrud AS | | 2020 |
| Marius Schultz AS | Arts & recreation | 2005 |
| Marius Stamnes Boktrykkeri AS | Manufacturing | 1965 |
| Marius Vik Tvedte AS | | 2022 |
| Marius VVS AS | Construction | 2025 |
| Mariusmandal AS | Information & communication | 2021 |
| Marjos AS | Real estate | 2017 |
| Mark Norge AS | Information & communication | 1996 |
| Mark Tomahawk AS | Real estate | 2015 |
| Marka Blomster AS | Agriculture & fishing | 2023 |
| Marka Sopp AS | Agriculture & fishing | 2026 |
| Marka Trails AS | Arts & recreation | 2025 |
| Markadoktorn AS | Health & social care | 2012 |
| Markajentene AS | Manufacturing | 2012 |
| Markakontor AS | Professional & scientific | 2022 |
| Markalleen 100 AS | Real estate | 2017 |
| Markalleen 114 AS | Real estate | 2008 |
| Markalleen Utvikling AS | Real estate | 2018 |
| Markandu Sports AS | Professional & scientific | 2024 |
| Markant Energy Norge AS | Wholesale & retail | 2020 |
| Markant Gruppen AS | Wholesale & retail | 2021 |
| Markberg Holding AS | | 2025 |
| Markedly Energy Group AS | Real estate | 2020 |
| Markedsakademiet Norges Markedsakademi AS | Professional & scientific | 2022 |
| Markedsavdelingen Nuf | Professional & scientific | 2010 |
| Markedseksperten AS | Professional & scientific | 2025 |
| Markedsføringsforeningen I Oslo Drift AS | Education | 2002 |
| Markedsinvest AS | Wholesale & retail | 1984 |
| Markedspilotene AS | Professional & scientific | 2023 |
| Markedsplassen Avd Bogstadveien AS | Wholesale & retail | 1997 |
| Markedssjefene AS | Professional & scientific | 2020 |
| Markedsteam AS | Professional & scientific | 1998 |
| Markem-Imaje AS | Wholesale & retail | 2006 |
| Markeng Holding AS | | 2025 |
| Marker Vindpark AS | Energy | 2015 |
| Markestranda & Omegn Vannlag SA | Water & waste | 2013 |
| Market Invest AS | Financial services | 2013 |
| Marketer 360 AS | Information & communication | 2025 |
| Marketer Agencies AS | Professional & scientific | 2019 |
| Marketing Toolbox AS | Professional & scientific | 2006 |
| Marketplace AS | Information & communication | 2016 |
| Markigroup AS | Professional & scientific | 2026 |
| Markintrade AS | Information & communication | 2026 |
| Markisehuset AS | Wholesale & retail | 2015 |
| Markku Karma AS | Health & social care | 2013 |
| Markløperen AS | Financial services | 2007 |
| Markmonitor Professional Services Inc. | Information & communication | 2008 |
| Marko AS | | 2024 |
| Marko-Trans AS | Transport & logistics | 2018 |
| Markom Uniformer Og Profilering AS | Wholesale & retail | 2024 |
| Markstøl Invest AS | Financial services | 2014 |
| Marktlink Norway M&A AS | Professional & scientific | 2026 |
| Markus Andresen Holding AS | | 2022 |
| Markus Gjelseth Invest AS | | 2017 |
| Markuskr Holding AS | | 2025 |
| Markussen Eiendom AS | Real estate | 2005 |
| Markussen Music AS | Arts & recreation | 2019 |
| Markuz AS | Professional & scientific | 2024 |
| Markveien 26 AS | Real estate | 2015 |
| Markveien 32 A-B AS | Real estate | 2013 |
| Markveien 32 F-G AS | Real estate | 2022 |
| Markveien 35 Property AS | Real estate | 2017 |
| Markveien 42 AS | Real estate | 2007 |
| Markveien 44 AS | Real estate | 2010 |
| Markveien 48 AS | Real estate | 2014 |
| Markveien 5 AS | Real estate | 2013 |
| Markveien 53 AS | Real estate | 2018 |
| Markveien 56 AS | Real estate | 2021 |
| Markveien 57 AS | Real estate | 2012 |
| Markveien Drueklubb Da | Administrative & support | 2024 |
| Markveien Eiendom AS | Real estate | 2024 |
| Markveien Helseklinikk AS | Health & social care | 2022 |
| Markveien Legesenter AS | Health & social care | 1996 |
| Markveien Mat & Vinhus AS | Hospitality | 1992 |
| Markveien Næring AS | Real estate | 2022 |
| Markåni Kraftverk AS | Energy | 2019 |
| Markør AS | | 2021 |
| Markøren Reklame AS | Professional & scientific | 2015 |
| Marla AS | | 2026 |
| Marlaas AS | | 2025 |
| Marlake Invest AS | | 2023 |
| Marldon Holding AS | Real estate | 2000 |
| Marlea AS | Real estate | 2017 |
| Marlef AS | Professional & scientific | 2020 |
| Marleohan Holding AS | Real estate | 2019 |
| Marley Media AS | Information & communication | 2026 |
| Marlik International Da | Professional & scientific | 1990 |
| Marlin Eiendom AS | Real estate | 2005 |
| Marlin Holding AS | Real estate | 2009 |
| Marlinda Holding AS | Financial services | 2021 |
| Marloks Holding AS | | 2025 |
| Marlou AS | | 2020 |
| Marlou Stylingbar & Café AS | Other services | 2019 |
| Marlus Holdings AS | | 2026 |
| Marlycon AS | Professional & scientific | 2014 |
| Marmara Da | Wholesale & retail | 1989 |
| Marmor Import Norge AS | Wholesale & retail | 2014 |
| Marmor Invest AS | Real estate | 2014 |
| Marmora AS | Wholesale & retail | 2024 |