| Marineholmen MK2 AS | Real estate | 2025 |
| Marineholmen Ocean Energy AS | Real estate | 2009 |
| Marineholmen Seniorboliger AS | Real estate | 2023 |
| Marineholmen Slippen AS | Real estate | 2009 |
| Marineholmen Stationen AS | Real estate | 2023 |
| Marineholmen Teaterbygg AS | Real estate | 2013 |
| Marinelaw AS | Transport & logistics | 1987 |
| Marinvest Energy AS | Energy | 2020 |
| Marit Voldsæter AS | Arts & recreation | 2000 |
| Maritime Tours AS | Transport & logistics | 2000 |
| Marius Byggservice AS | Construction | 2026 |
| Marivida AS | Information & communication | 2025 |
| Mark Iversen Elektrisk Engros AS | Wholesale & retail | 1944 |
| Marka Utbygging AS | Real estate | 2016 |
| Markeik Holding AS | | 2026 |
| Marken 11-H0101 Og H0102 AS | Real estate | 2024 |
| Marken 19 AS | Real estate | 2013 |
| Marken 26 AS | Real estate | 2021 |
| Marken 37 AS | Real estate | 2016 |
| Marken Dagligvare AS | Wholesale & retail | 2024 |
| Marken Eiendom AS | Real estate | 2004 |
| Marken Kaffe AS | Hospitality | 2025 |
| Marken Næringseiendom AS | Real estate | 2025 |
| Marken Utvikling AS | Real estate | 2009 |
| MARKEN9 AS | Hospitality | 2025 |
| Markens Eiendom AS | Real estate | 2020 |
| Markens Tverrgate 13 AS | Real estate | 2011 |
| Markesmuget Eiendom AS | Real estate | 2017 |
| Markeveien 1 B AS | Real estate | 2019 |
| Markeveien 1 B Hjemmel AS | Real estate | 2007 |
| Markeveien 10 AS | Wholesale & retail | 1936 |
| Markeveien 4A AS | Real estate | 2009 |
| Markeveien 4B AS | Real estate | 2015 |
| Markeveien 4C AS | Real estate | 2012 |
| Markeveien Eiendom AS | Real estate | 2005 |
| Markeveien Fysioterapi Ans | Health & social care | 2003 |
| Markusplass Næring 1 AS | Real estate | 2017 |
| Markør Kommunikasjon Ans | Professional & scientific | 2011 |
| Marmida AS | Financial services | 2016 |
| Marmorhagen AS | Real estate | 2019 |
| Mars Eiendom AS | Real estate | 2022 |
| Mars Invest AS | Real estate | 2022 |
| Marsoma AS | | 2025 |
| Marte Holding AS | | 2023 |
| Martens Management AS | Professional & scientific | 2021 |
| Martigny AS | Hospitality | 2005 |
| Martin Aadland Holding AS | | 2025 |
| Martin Gavlen AS | | 2023 |
| Martin Vahlsgate 11 Ans | Real estate | 2006 |
| Martinez Invest AS | Professional & scientific | 2021 |
| Martinussen Tradisjon Og Kompetanse (M T & K) AS | Professional & scientific | 2020 |
| Maryal AS | Real estate | 2008 |
| Masgh AS | | 2025 |
| Master Trykk Og Profilering AS | Manufacturing | 2000 |
| Masterbulk AS | Transport & logistics | 2019 |
| Mastervet AS | Professional & scientific | 2011 |
| Matae AS | Professional & scientific | 2022 |
| Matae Bergen AS | Professional & scientific | 2023 |
| Matarena AS | Administrative & support | 2014 |
| Matbu AS | Hospitality | 2020 |
| Mathis Eiendom AS | Real estate | 2023 |
| Mathisen Holding AS | Wholesale & retail | 2005 |
| Mathisen Invest & Eiendom AS | Financial services | 2005 |
| Mathisen Service AS | Real estate | 2016 |
| Mathopsveien 58 AS | Real estate | 2014 |
| Matias AS | | 2022 |
| Matje AS | Professional & scientific | 2022 |
| Mato Forvaltning AS | Administrative & support | 2026 |
| Mato Holdings AS | | 2024 |
| Matrio AS | | 2025 |
| Matro AS | Health & social care | 2025 |
| Mats Vatnøy Holding AS | | 2024 |
| Matsle AS | | 2025 |
| Mattis Invest AS | Financial services | 2005 |
| Maud AS | Real estate | 2015 |
| Maur AS | | 2021 |
| Maurset Service AS | Real estate | 2019 |
| Maursetparken AS | Construction | 2018 |
| Maursettoppen AS | Real estate | 2022 |
| Mavesi Invest AS | Real estate | 2019 |
| Mavisu AS | | 2020 |
| Max Beauty AS | Other services | 2016 |
| Max Great AS | Information & communication | 2024 |
| Max Milan Frisør AS | Other services | 1991 |
| Maxi Bingo AS | Arts & recreation | 2011 |
| Maxim Parfymeri AS | Wholesale & retail | 2008 |
| Maxwork AS | Information & communication | 2015 |
| MB Elektro AS | Construction | 2019 |
| MB Energy AS | Wholesale & retail | 2019 |
| MB Konserntjenester AS | Professional & scientific | 2000 |
| Mb.Holding AS | Construction | 2021 |
| MC Sentralen Ans | Transport & logistics | 1992 |
| Mcdonnell & Mannion Limited | Construction | 2012 |
| Mcee Advokatkontor AS | Administrative & support | 2021 |
| Mdco Bergen AS | Health & social care | 1999 |
| Mdo Holding AS | | 2026 |
| Meats AS (Manufacturing Execution and Traceability Systems) | Wholesale & retail | 2010 |
| Mechs AS | | 2021 |
| Medgang AS | Real estate | 2025 |
| Media Bergen AS | Professional & scientific | 1990 |