| Aeonian 45 AS | | 2026 |
| Aeonian 46 AS | | 2026 |
| Aer Invest AS | | 2022 |
| Aera Geoenergy AS | Energy | 2025 |
| Aerke AS | Professional & scientific | 2024 |
| Aeronauticonsult AS | Professional & scientific | 2006 |
| Aeronautiholding AS | Professional & scientific | 2005 |
| Aesa Invest AS | | 2019 |
| Aet Norway AS | Professional & scientific | 2021 |
| Aeth Holding AS | Information & communication | 2023 |
| Af Eikeland AS | Information & communication | 2025 |
| Affi AS | Wholesale & retail | 2015 |
| Afonso Franco AS | Professional & scientific | 2023 |
| Afro Hair & Art AS | Other services | 2011 |
| Aftermath AS. | | 2021 |
| AG Kapital AS | | 2026 |
| Agathon Holding AS | | 2023 |
| Agdal Management AS | Professional & scientific | 1999 |
| Ageko AS | Real estate | 2006 |
| Agendec AS | Information & communication | 1986 |
| Agent Kommunikasjon AS | Professional & scientific | 1991 |
| Agenten Invest AS | Health & social care | 2007 |
| Agentic Holding AS | | 2026 |
| Agil HMS AS | Health & social care | 2019 |
| Agila AS | Financial services | 2009 |
| Agk Consult AS | Professional & scientific | 2019 |
| Agl Invest AS | Financial services | 2007 |
| Agora Partners AS | Professional & scientific | 2024 |
| Agp Investments AS | Construction | 2012 |
| Agr Consultancy Services AS | Administrative & support | 2006 |
| Agr Group Field Operations Inc | Professional & scientific | 2010 |
| Agro Transport AS | Transport & logistics | 2020 |
| Agrovisjon AS | Other services | 2021 |
| Agvs Holding AS | | 2024 |
| Ahb Holdingselskap AS | | 2024 |
| Ahead Eiendom AS | Real estate | 2009 |
| Ahlqvist Holding AS | | 2014 |
| Ahodzil AS | Information & communication | 2023 |
| AI Invest AS | | 2023 |
| AI Legal Compliance AS | Professional & scientific | 2025 |
| Aikon AS | Professional & scientific | 2026 |
| Aiolos Investering AS | Financial services | 2003 |
| Aion Invest AS | Financial services | 2007 |
| Air & Energy AS | Construction | 2015 |
| Air Total International SA | Wholesale & retail | 1998 |
| AIR2WORK AS | Professional & scientific | 2015 |
| Airport Infrastructure AS | Real estate | 2020 |
| Aisus Offshore AS | Professional & scientific | 2025 |
| Aiventix AS | Professional & scientific | 2020 |
| Aivero AS | Information & communication | 2017 |
| Aj Berge Holding AS | | 2024 |
| Aj Bra Service AS | Health & social care | 2017 |
| Aj Company AS | Wholesale & retail | 2015 |
| Ajax Eiendom AS | Real estate | 2012 |
| Ajestra Group AS | | 2026 |
| Ak Malerservice AS | Construction | 2019 |
| Ak-Lifting AS | Manufacturing | 2015 |
| Aka Holding AS | Financial services | 2012 |
| Akari Holding AS | | 2026 |
| Akasiablooms AS | | 2018 |
| Akaso Elektro AS | Construction | 2010 |
| Akbas Invest AS | Hospitality | 2022 |
| Akf Investering AS | Professional & scientific | 2010 |
| Akh Consulting AS | Professional & scientific | 2015 |
| Akkord Rogaland- Målekontor for Byggfag SA | Other services | 2022 |
| Aknaton AS | Real estate | 2014 |
| Akr Finans AS | Financial services | 2005 |
| Akre Consulting AS | Information & communication | 2014 |
| Akre Holding AS | Wholesale & retail | 2008 |
| Aksada AS | | 2026 |
| Aksay Holding AS | | 2025 |
| Aksdal Invest AS | Construction | 2008 |
| Aksiom Investering AS | Real estate | 2012 |
| Aksjeselskap Ekelund & Erlandsen | Professional & scientific | 2021 |
| Aksjeselskapet Fomp | Education | 2019 |
| Aksjeselskapet Tempo | Administrative & support | 2001 |
| Aktiebryggeriet AS | Real estate | 2018 |
| Aktiv Beredskap AS | Health & social care | 2013 |
| Aktiv HMS Prosjekt AS | Health & social care | 2013 |
| Aktiv Kunnskap AS | Education | 1988 |
| Aktiv Sprinkler AS | Professional & scientific | 2002 |
| Aktive Hoder AS | Arts & recreation | 2016 |
| Akuna AS | Professional & scientific | 2017 |
| Akv Holding AS | Construction | 2022 |
| Akvaguiden AS | Information & communication | 2023 |
| Akvatotal AS | Professional & scientific | 2014 |
| Aladdin Cuisine AS | Hospitality | 2020 |
| Alameda Holding AS | | 2016 |
| Alandyk Invest AS | Professional & scientific | 2020 |
| Alara Holding AS | | 2025 |
| Alas AS | Professional & scientific | 2025 |
| Albemarle Invest 2 AS | Financial services | 2013 |
| Albemarle Invest 3 AS | | 2022 |
| Albemarle Invest AS | Financial services | 2009 |
| Albretsen Holding AS | Professional & scientific | 2005 |
| Aldente Kommunikasjonsbyrå AS | Professional & scientific | 2006 |
| Aldri Mer AS | Hospitality | 2014 |
| Alef Holdings AS | | 2026 |
| Alere AS | | 2021 |
| Aletho AS | Wholesale & retail | 2010 |