| 1875 Group AS | Information & communication | 2026 |
| 1875 Information Services AS | | 2026 |
| 1875 Opplysningstjenester AS | Information & communication | 2026 |
| 47 Elleve AS | Real estate | 2018 |
| 4R3 Equity AS | | 2024 |
| 4R3 Service AS | Construction | 2025 |
| 8 Høyre AS | Real estate | 2019 |
| 911-TJENESTEN AS | Information & communication | 1998 |
| A Solvang AS | | 2025 |
| A Trade AS | Financial services | 2005 |
| A Woxen Eiendom AS | Construction | 2024 |
| A7 Media AS | Professional & scientific | 2024 |
| Aa Holding AS | Financial services | 2005 |
| Aaj AS | Real estate | 2012 |
| Aaj Eiendom AS | Real estate | 2013 |
| Aaltvedt Snekkerservice AS | Construction | 2024 |
| Aanonsen Eige Da | Agriculture & fishing | 2016 |
| Aasgrav - Personlig Trening Og Fysioterapi AS | Education | 2023 |
| Aasland Teknikk AS | Wholesale & retail | 2005 |
| Ab-Maritim AS | Wholesale & retail | 2018 |
| Abc Video Da | Administrative & support | 1989 |
| Absolute Holding AS | | 2020 |
| Accounthelp AS | Professional & scientific | 2025 |
| Act Heistad AS | Real estate | 1998 |
| Activ Norge Ans | Wholesale & retail | 1995 |
| Addcon Nordic AS | Manufacturing | 2005 |
| Admini AS | Real estate | 2019 |
| Adrian Halland AS | Health & social care | 2015 |
| Adurna AS | Real estate | 2002 |
| Advokatfirma Geirr Frønes AS | Professional & scientific | 2014 |
| Advokatfirma Jason Alexander Werner AS | Professional & scientific | 2025 |
| Advokatfirma Mjaaseth AS | Professional & scientific | 2013 |
| Advokatfirma Mjaaseth Revheim Co Da | Professional & scientific | 2017 |
| Advokatfirma Skomvær Da | Professional & scientific | 2010 |
| Advokatfirma Thorkildsen & Sem Da | Professional & scientific | 1992 |
| Advokatfirmaet Hein Bæra AS | Professional & scientific | 2016 |
| Advokatfirmaet Mofossbakke AS | Professional & scientific | 2024 |
| Advokatfirmaet Revheim AS | Professional & scientific | 2015 |
| Aejo AS | Professional & scientific | 2026 |
| Afg Eiendom AS | Real estate | 2019 |
| Afood Porsgrunn AS | Wholesale & retail | 2022 |
| Afro Cutz AS | Other services | 2025 |
| Ageto AS | Real estate | 2004 |
| Agilenor Holdings AS | Wholesale & retail | 2018 |
| Ah & RH Da | Real estate | 2011 |
| Ahlbom Holding AS | Real estate | 2007 |
| Aicono AS | Professional & scientific | 2019 |
| Aicono Gruppen AS | Real estate | 2023 |
| Aicono Management AS | Professional & scientific | 2024 |
| Aiko AS | | 2024 |
| Ainir Cyclotronics AS | Professional & scientific | 2024 |
| Aks Bensindrift AS | Wholesale & retail | 2018 |
| Aktiv Veiledning AS | Health & social care | 2014 |
| Alberts Boligutleie AS | Real estate | 2024 |
| Aleksandria Motor AS | Wholesale & retail | 2012 |
| Alfa Bilpleie AS | Other services | 2025 |
| Alfa Smådyrklinikk AS | Professional & scientific | 2005 |
| Alfred Invest AS | Real estate | 2016 |
| Algenatura AS | Manufacturing | 2020 |
| ALI1 AS | Professional & scientific | 2012 |
| Allianse Concept AS | Real estate | 2016 |
| Allimak Holding AS | Financial services | 2016 |
| Allsidium AS | Information & communication | 2019 |
| Alpha Godstransport AS | Transport & logistics | 2023 |
| Altrad Utstyr AS | Administrative & support | 2025 |
| Alua Holding AS | Financial services | 2018 |
| Alytus 2 Limited Nuf | Real estate | 2010 |
| Alytus AS | Real estate | 2009 |
| Am Sivertsen Holding AS | | 2022 |
| Amalu Invest AS | | 2026 |
| Amanda Tufte Holding AS | | 2025 |
| Amante Porsgrunn AS | Other services | 2026 |
| Amax Bygg AS | Construction | 2018 |
| Amax Bygg Ny AS | Construction | 2023 |
| Amax Holding AS | Construction | 2023 |
| Amea AS | Real estate | 2006 |
| Amg Invest AS | Financial services | 2008 |
| Amora Studio AS | Professional & scientific | 2026 |
| Amrani Engineering & Project Management AS | Professional & scientific | 2026 |
| Amrani Group AS | | 2026 |
| Amundsen Ventilasjon Holding AS | Construction | 2021 |
| Amwj AS | Professional & scientific | 2017 |
| Anders Baars Veg AS | Real estate | 2022 |
| Anders Hegna Holding AS | Wholesale & retail | 2005 |
| Andersens AS | Other services | 2022 |
| Andr Aasland AS | Wholesale & retail | 1970 |
| Andreas Aasland Gårdselskapet Ans | Real estate | 1995 |
| Andreas Woxen Holding AS | Construction | 2023 |
| Andvik Propellers AS | Manufacturing | 2024 |
| Angels Touch Production Ans | Information & communication | 2008 |
| Anleggsgartner Nordengen AS | Administrative & support | 2019 |
| Anleggshjelpen AS | Construction | 2016 |
| Ans Karlsen & Sønner | Water & waste | 1978 |
| Antagonist AS | Information & communication | 2014 |
| Antonsen Auto AS | Wholesale & retail | 2024 |
| Apollo Pizza Grill AS | Hospitality | 2024 |
| Ar & Husma Holding AS | | 2026 |
| Arbeidsmiljø- & Sikkerhetskompetanse Da | Professional & scientific | 2000 |
| Arctic Biowave Systems AS | Professional & scientific | 2024 |
| Arctic Business Corporation AS | Real estate | 2017 |