| Maya Tomter AS | Real estate | 2005 |
| Mayblomsten AS | | 1996 |
| Mayfair Capital AS | Real estate | 2013 |
| Mayfair Consulting Group AS | Professional & scientific | 2024 |
| Mayhem AS | Arts & recreation | 2016 |
| Maykev AS | Real estate | 2020 |
| Maykol AS | Transport & logistics | 2001 |
| Mayland Holding AS | | 2024 |
| Maynard Solomon Invest AS | Administrative & support | 2018 |
| Mayu Designs AS | Wholesale & retail | 2021 |
| Maz Bud Ryszard Mazurkiewicz | Construction | 2010 |
| Maza Invest AS | Real estate | 2012 |
| Mazal Invest AS | Hospitality | 2023 |
| Mazar AS | Hospitality | 2013 |
| Maze Feedback AS | Information & communication | 1998 |
| Mazeppa Holding AS | Information & communication | 2019 |
| Mazeppa Norge AS | Information & communication | 2014 |
| Mazo Invest AS | | 2024 |
| Mazur Holding AS | | 2025 |
| Mazurka Invest AS | | 2021 |
| MB 6-8 Invest AS | Real estate | 2022 |
| MB Annonsebyrå Ans | | 1989 |
| MB Aringa Namai Nuf | Administrative & support | 2026 |
| MB Bjørk Prosjekt AS | Real estate | 2020 |
| MB Business Development AS | Professional & scientific | 2017 |
| MB Byggeledelse AS | Professional & scientific | 2023 |
| MB Capital AS | Real estate | 2016 |
| MB Equity AS | | 2026 |
| MB Handel AS | Wholesale & retail | 2026 |
| MB Hotellkonsult AS | Professional & scientific | 2024 |
| MB INVEST786 AS | Hospitality | 2024 |
| MB Maler- Og Servicefirma AS | Construction | 2022 |
| MB Property 1 AS | Real estate | 2024 |
| MB Property 2 AS | Real estate | 2009 |
| MB TBD 2 AS | Real estate | 2018 |
| MB TBD 3 AS | Real estate | 2020 |
| MB Technology Invest AS | | 2013 |
| MB Total Entreprenør AS | Construction | 2022 |
| MB Work & Construction Nuf | Construction | 2021 |
| Mb-Sveda AB | Wholesale & retail | 1995 |
| MB7 I AS | Real estate | 2014 |
| Mb:Ark AS | Professional & scientific | 2008 |
| Mba Eiendom Gruppen Ans | Real estate | 1996 |
| Mba Holding AS | Financial services | 2014 |
| Mba Strategier AS | Professional & scientific | 2026 |
| Mbarete AS | | 2017 |
| MBB Capital AS | | 2026 |
| Mbbc AS | Real estate | 2021 |
| MBD Entreprenør AS | Construction | 2025 |
| Mbegani AS | Real estate | 2003 |
| MBF Tomta AS | Real estate | 2008 |
| MBG2 AS | Real estate | 2020 |
| MBH Capital AS | | 2025 |
| Mbi Invest AS | Financial services | 2005 |
| MBJ Retail Bergen AS | Wholesale & retail | 2020 |
| MBJ Retail Norge AS | Wholesale & retail | 2018 |
| MBL Invest AS | | 2024 |
| MBL Medisinsk Basislitteratur AS | Information & communication | 1995 |
| Mbmc Invest AS | Real estate | 2021 |
| Mbo Holding AS | Professional & scientific | 2018 |
| MBR 118 Holding AS | | 2023 |
| MBR Byggtjenester AS | Construction | 2026 |
| MBR Holding AS | | 2026 |
| MBS Ventures AS | Information & communication | 2025 |
| Mbsc Norge AS | Other services | 2018 |
| Mbsg Invest AS | | 2026 |
| Mbsr Holding AS | Transport & logistics | 2022 |
| Mbu Invest AS | Financial services | 2015 |
| Mburfjell Holding AS | | 2025 |
| Mbxp Norge AS | Administrative & support | 2013 |
| Mbyg Construction AS | Construction | 2023 |
| Mbygg AS | Construction | 2020 |
| Mbyr Holding AS | | 2025 |
| MC Hammer Invest AS | Real estate | 2019 |
| MC Kenna Design Nuf | Construction | 2024 |
| MC Oslo AS | Wholesale & retail | 2017 |
| MC Oslo Services AS | Wholesale & retail | 2021 |
| MC Prefab Nordics AS | Information & communication | 2021 |
| MC Spreco Bygg AS | Construction | 2024 |
| MC Touring Trafikkskole AS | Education | 1996 |
| MC Ullevål AS | Real estate | 2010 |
| Mc-Produksjon AS | Real estate | 2016 |
| MCB AS | Wholesale & retail | 2020 |
| MCB Sportswear AS | Wholesale & retail | 2024 |
| Mcbrenne AS | | 2026 |
| Mccmo Holding AS | | 2022 |
| Mcdowall Holdings AS | | 2021 |
| Mcflai AS | Information & communication | 2025 |
| Mcgovern Helse AS | Health & social care | 2025 |
| Mcgraw-Hill International (UK) Ltd | Administrative & support | 2001 |
| Mchb AS | Professional & scientific | 2025 |
| Mcih AS | | 2021 |
| MCK Holding AS | | 2024 |
| MCK Invest AS | | 2024 |
| Mckenna Capital AS | Real estate | 2015 |
| MCKINSEY & COMPANY INC NORWAY norsk avdeling av utenlandsk foretak NUF | Professional & scientific | 1995 |
| Mclean Projects & Investments AS | Professional & scientific | 2016 |
| Mcleod Holdings AS | | 2025 |
| MCM AS | Professional & scientific | 2006 |
| MCM Invest AS | Real estate | 2015 |