| Loge Resources AS | Nesøya | 2005 |
| London Offshore Consult Ltd | London Ec3N 1Dy | 1995 |
| LTG Invest AS | Sarpsborg | 2005 |
| Lu Cap AS | Oslo | 2021 |
| Luna Industri AS | Aurland | 2004 |
| Luna Mineral AS | Aurland | 2004 |
| Lundhs Aggregates AS | Larvik | 2021 |
| Lundhs AS | Larvik | 2008 |
| Lunner Pukkverk AS | Lunner | 1983 |
| Lynx Offshore AS | Oslo | 2018 |
| Lysekloster Miljøpark AS | Tysnes | 2026 |
| M S S (Scotland) Limited | Stranraer Dg9 7Lw | 2018 |
| M Vest AS | Paradis | 2015 |
| M Vest Energy AS | Bergen | 2015 |
| M Vest Invest 2 AS | Bergen | 2022 |
| M Vest Invest AS | Bergen | 2016 |
| Maats Tech Ltd | Gloucester Gl2 9Ql | 2014 |
| Macartney A/S | Stavanger | 1999 |
| Macro Offshore Operations AS | Sandnes | 2025 |
| Macro Offshore Services AS | Sandnes | 2026 |
| Magnesium Alloys Norway AS | Oslo | 2018 |
| Mala Og Nummedal Skiferdrift Ans | Voss | 1992 |
| Malmberg Borrning AB | Moss | 2013 |
| Mangerud AS | Rådal | 2018 |
| Mangor AS | Tønsberg | 2021 |
| Manito AS | Hauge I Dalane | 2005 |
| Maraen Fabrication Limited | Ross-Shire Iv19 1Qu Scotland | 2013 |
| Marc.J.M Limited Nuf | Tananger | 2024 |
| Mardahl Industri AS | Orkanger | 2005 |
| Marenco Investments Ltd | Oslo | 2001 |
| Marigold Holdco AS | Lysaker | 2025 |
| Maris Subsea Ltd | Aberdeen Ab21 7Gq | 2025 |
| Maritech Consultants Ltd | Norfolk Nr30 2Qh England | 1995 |
| Maritim Norge AS | Voll | 2006 |
| Marvel Commissioning Limited | Ne33 4Jd Tyne And Wear | 2016 |
| Maskin Drift AS | Kvål | 2013 |
| Maxtube Limited | Aberdeen Ab10 1Ha | 2014 |
| Mcpherson AS | Oslo | 2024 |
| Mekjarvik Eiendom AS | Randaberg | 2011 |
| Mela Stein AS | Larvik | 1989 |
| Melcal Marine UK Limited Nuf | Aberdeen Ab15 4Dt Scotland | 2026 |
| Melum Invest AS | Skien | 2022 |
| Melum Maskinutleie AS | Skien | 2022 |
| Meridian Shipping Services Pte Ltd | Sg-609277 Singapore | 1996 |
| Merlin Mud Service Ltd | Suffolk Nr33 7Nq | 2018 |
| Mesh Global Limited | Somerset Bs24 8Ee | 2021 |
| Metal Prospecting AS | Limingen | 2007 |
| Metall AS | Oslo | 2025 |
| Meteva AS | Blomsterdalen | 2005 |
| Metrol Technology Limited | Aberdeen Ab21 0Gu Scotland | 1995 |
| Metrol Technology Norway AS | Oslo | 2023 |
| Mhwirth GmbH | De-41812 Erkelenz | 2023 |
| Mibau Stema Norge AS | Jelsa | 1990 |
| Midrock AS | Oppdal | 2023 |
| Midrock Oppdal AS | Oppdal | 2009 |
| Miljøskifer AS | Lensvik | 2019 |
| Mill Wynd Ltd | Glasgow G2 4Jr Scotland | 2021 |
| Minera Pukk AS | Drivdalen | 2024 |
| Mineral Holding AS | Lier | 2011 |
| Mineral Improvment Limited | Nedstrand | 1999 |
| Minerall AS | Ålgård | 2021 |
| Mineralressurs AS | Oteren | 2024 |
| Minerals Group AS | Stavanger | 2008 |
| Mining AS | Risøyhamn | 1998 |
| Mira Repstad AS | Kristiansand S | 2004 |
| ML Pukk AS | Rena | 2013 |
| Mo Grus AS | Melhus | 2014 |
| Mo I Rana VMS AS | Lysaker | 2021 |
| Mobilgrus AS | Tynset | 2011 |
| Mobilknusing Midt-Norge AS | Støren | 2009 |
| Mobilknusing Nord AS | Rossfjordstraumen | 2025 |
| Modalen Sandtak AS | Modalen | 2012 |
| Modi Vivendi AS | Oslo | 2005 |
| Moduspec Ltd | Westhill Ab32 6Fg | 1996 |
| Mohn Drilling AS | Laksevåg | 1985 |
| Mohr AS | Hafrsfjord | 2010 |
| Mokveld Valves BV | Stavanger | 1995 |
| Moldreim Skifer AS | Utvik | 1996 |
| Monarch Geophysical Services Limited | Sandnes | 2014 |
| Mongstad Terminal Da | Mongstad | 2001 |
| Monzonite AS | Larvik | 1984 |
| Moore Energy AS | Oslo | 2009 |
| More Holdco Apply AS | Stavanger | 2016 |
| Moreld Group AS | Stavanger | 2023 |
| Motive Rentals Ltd | Aberdeenshire Ab45 2Lr | 2013 |
| MQ Granite AS | Kautokeino | 2010 |
| MR. Pukk Høland AS | Løken | 1989 |
| MR. Pukk Øst AS | Mysen | 1962 |
| Msak Ltd | En6 3Dq Hertfordshire | 2016 |
| Muddy Water Diving | Se- 612 60 Mellbystrand | 2019 |
| Mustorp Grustak Da | Mysen | 2002 |
| Myrhaug Marine AS | Smøla | 2018 |
| Myrstrand Torvfabrikk Ans | Våler I Solør | 1990 |
| Myrstrand Torvfabrikk AS | Våler I Solør | 2006 |
| Mythe Systems Limited | Gb-Norfolk Nr6 6Bb | 2016 |
| Molde Pukkverk AS | Molde | 1978 |
| Mårlund Grustak AS | Uvdal | 2025 |
| Mølleng Maskin & Pukk AS | Storslett | 1996 |
| Mønsberget AS | Voss | 2020 |
| N C Sheridan Limited Nuf | Bt22 2Lu Newtownards, Co Down Ni | 2025 |