| Marmori AS | | 2019 |
| Marna Invest AS | | 2006 |
| Marni Holding AS | Financial services | 2017 |
| Marnic AS | | 1994 |
| Marnos Holding AS | Real estate | 2012 |
| Maro Capital AS | | 2020 |
| Maro Øl AS | Wholesale & retail | 2021 |
| Marolo Holding AS | | 2021 |
| Maron Anlegg AS | Transport & logistics | 2012 |
| Maron Invest AS | | 2021 |
| Marone Brovoll Invest AS | Real estate | 2022 |
| Marong Holding AS | | 2023 |
| Maroon Bells AS | Professional & scientific | 2023 |
| Maroy AS | Real estate | 2004 |
| Marpa Invest AS | Transport & logistics | 2021 |
| Marqt.No AS | Wholesale & retail | 2020 |
| Marquee AS | Information & communication | 2015 |
| Marques Sourcing AS | | 2026 |
| Marquistech AS | Information & communication | 2025 |
| Marrakech AS | Hospitality | 2004 |
| Marrern Holding AS | | 2026 |
| MARRIAGE4LIFE Application AS | Information & communication | 2025 |
| MARRIAGE4LIFE Consulting AS | Other services | 2026 |
| MARRIAGE4LIFE Development AS | Information & communication | 2026 |
| Marrim Ventures AS | | 2020 |
| Marriott Aerospace Technology AS | Information & communication | 2016 |
| Marron AS | Professional & scientific | 2013 |
| Marrot AS | Professional & scientific | 2025 |
| Marrylou Enterprises AS | | 2026 |
| Mars Electronics AS | Information & communication | 2026 |
| Mars Holding AS | Information & communication | 2013 |
| Mars Norge AS | Wholesale & retail | 1973 |
| Mars Property AS | Real estate | 2021 |
| Mars Protocol AS | | 2021 |
| Marselia Robotics AS | Information & communication | 2025 |
| Marsh Mclennan AS | Financial services | 1987 |
| Marshall Norway AS | Administrative & support | 2012 |
| Marshmallow Holding AS | | 2026 |
| Marshmallow Partners AS | Professional & scientific | 1973 |
| Marshmallows AS | | 2024 |
| Marsian Invest AS | | 2025 |
| Marsilius Holding AS | | 2023 |
| Marsimonsen AS | Arts & recreation | 2017 |
| Marsipan Compagniet AS | Manufacturing | 2016 |
| Marsko AS | | 2026 |
| Marstad Group AS | Information & communication | 2021 |
| Marstein AS | Professional & scientific | 2017 |
| Marstein Psykologklinikk AS | Health & social care | 2026 |
| Marstrand Advokatfirma AS | Professional & scientific | 2018 |
| Marstrand AS | Professional & scientific | 2014 |
| Marstrand Digi AS | Professional & scientific | 2020 |
| Marstrandgata 6 AS | Real estate | 2008 |
| Marstrandgata 6 Da | Real estate | 1991 |
| Marstrandgata 9 & 11 AS | Real estate | 2017 |
| Marstrandgata 9 & 11 Holding AS | Real estate | 2022 |
| Marstrandgata 9 &11 Prosjekt AS | Real estate | 2016 |
| Marstrandsgata 10A AS | Real estate | 2026 |
| Marstrandsgata 10B AS | Real estate | 2026 |
| Marsvin Invest AS | Financial services | 2012 |
| Marta Huglen Revheim AS | Arts & recreation | 2023 |
| Marte Gleditsch Holding AS | | 2023 |
| Marte Vidje AS | Professional & scientific | 2020 |
| Marte Wulff AS | Arts & recreation | 2023 |
| Martebakken 3 AS | Real estate | 2019 |
| Martebf Holding AS | | 2025 |
| Martec AS | Wholesale & retail | 2020 |
| Martech AS | Information & communication | 2024 |
| Martech Invest AS | | 2020 |
| Martela AS | Wholesale & retail | 1990 |
| Martello Consulting AS | Information & communication | 2024 |
| Martellus AS | Real estate | 1983 |
| Martens Invest AS | | 2021 |
| Martens Takst AS | Real estate | 2015 |
| Marthej Consulting AS | Professional & scientific | 2023 |
| Marthinsen & Co AS | Transport & logistics | 2021 |
| Marthor AS | | 2025 |
| Marti AS | Construction | 2011 |
| Marti Risdal Holding AS | | 2024 |
| Marti Technik AG | Professional & scientific | 2022 |
| Martilobo AS | Construction | 2022 |
| Martiluca AS | | 2021 |
| Martin Fidem AS | Administrative & support | 2002 |
| Martin Fjeld AS | Professional & scientific | 2026 |
| Martin Gabrielsen Invest AS | Education | 2016 |
| Martin Gnecco Holding AS | | 2026 |
| Martin Gran AS | Professional & scientific | 2010 |
| Martin Grimshave AS | Wholesale & retail | 2020 |
| Martin Haug Invest AS | Financial services | 2005 |
| Martin Hunvik AS | | 2021 |
| Martin Ihler Holding AS | | 2022 |
| Martin Johansen Invest AS | Real estate | 2016 |
| Martin Josephsen AS | Professional & scientific | 2023 |
| Martin Linges Vei 33 AS | Real estate | 2011 |
| Martin Medical Group AS | Professional & scientific | 2021 |
| Martin Møllhausen Holding AS | Real estate | 2018 |
| Martin Rasch Ersdal AS | Professional & scientific | 2020 |
| Martin Rosland AS | | 2023 |
| Martin Røe Holding AS | Administrative & support | 2021 |
| Martin Selen AS | Information & communication | 2024 |
| Martin Unlimited AS | | 2023 |