| A3 Gruppen AS | Construction | 2022 |
| A3PP AS | Professional & scientific | 2022 |
| A4 Bygg AS | Construction | 2014 |
| A4 Fiskebrygga AS | Real estate | 2012 |
| A4 Holding AS | Wholesale & retail | 2023 |
| A4 Sadelmakerbryggen AS | Real estate | 2018 |
| A5 Film AS | Information & communication | 2019 |
| A5 Group AS | Professional & scientific | 2025 |
| A5 Sadelmakerhullet AS | Real estate | 2008 |
| A6 Power AS | Transport & logistics | 2022 |
| A69 Invest AS | | 2024 |
| A9 Invest AS | | 2023 |
| A9 Palekaia AS | Real estate | 2008 |
| A9 Power AS | Wholesale & retail | 2024 |
| A95 Invest AS | | 2022 |
| Aa & SP Rådgivning AS | Financial services | 2020 |
| Aa Colors AS | Construction | 2024 |
| Aa Eiendomsinvest AS | | 2021 |
| Aa Equity Partners AS | Wholesale & retail | 2026 |
| Aa Kapital AS | | 2026 |
| Aa Nordic Consult AS | Information & communication | 2018 |
| Aa Pharma AB | Wholesale & retail | 2000 |
| Aa Sort Hvitt Bildeshop Ans | Manufacturing | 1990 |
| Aa Taxi AS | Transport & logistics | 2024 |
| Aa-Tverrelva Kraft AS | Energy | 2012 |
| AA30 Holding AS | Real estate | 2020 |
| Aaa Group AS | | 2025 |
| Aaa Invest AS | | 2024 |
| Aaa Investment AS | Administrative & support | 2021 |
| Aaaa Holding AS | | 2023 |
| Aaaa Tøyen Tannlegevakt AS | Health & social care | 2017 |
| Aaasen Holding AS | | 2025 |
| Aabakken AS | Professional & scientific | 2006 |
| Aabel AS | | 2018 |
| Aabel Holding AS | Hospitality | 2020 |
| Aabel Medical AS | Health & social care | 2023 |
| Aabeline AS | Financial services | 2021 |
| Aabelvik Invest AS | | 2026 |
| Aaberg Eiendom AS | Real estate | 2005 |
| Aaberg Eiendomsdrift AS | Construction | 2009 |
| Aaberg Invest AS | Financial services | 2018 |
| Aaby Holding AS | Real estate | 2016 |
| Aabyfjord Invest AS | Financial services | 2010 |
| Aabø-Evensen & Co Advokatfirma AS | Professional & scientific | 2002 |
| Aada Holding AS | Other services | 2022 |
| Aadne Holding AS | Arts & recreation | 2013 |
| Aadnevik Invest AS | Information & communication | 2018 |
| Aae 001 AS | Real estate | 2022 |
| Aae Invest AS | Financial services | 2017 |
| Aaeco Holding AS | Energy | 2019 |
| Aag Holding AS | Arts & recreation | 2024 |
| Aagaard Agency AS | Professional & scientific | 2017 |
| Aage Kjøs Holding AS | | 2005 |
| Aage Pettersen AS | Wholesale & retail | 1966 |
| Aage Storms Eftf. AS | Real estate | 2015 |
| Aah Arkitektur AS | Professional & scientific | 2026 |
| Aah Jackson AS | Professional & scientific | 2025 |
| Aahs Holding AS | | 2024 |
| Aak Norway AS | Wholesale & retail | 2005 |
| Aake Forvaltning AS | | 2025 |
| Aakermann AS | Real estate | 2005 |
| Aakf AS | | 2024 |
| Aakvik AS | Information & communication | 2024 |
| Aal AS | | 2026 |
| Aala AS | | 2024 |
| Aaland Invest AS | | 2024 |
| Aalerudmyra AS | Construction | 2012 |
| Aalinvest AS | Real estate | 1945 |
| Aall-In AS | Professional & scientific | 2025 |
| Aalls AS | Real estate | 2015 |
| Aalto Capital AS | Professional & scientific | 2011 |
| Aalund Nordic Danmark Nuf | Professional & scientific | 2007 |
| Aamodt Investment AS | | 2022 |
| Aamodt Ventures AS | Professional & scientific | 2018 |
| Aandahl Holding AS | | 2019 |
| Aaneland & Ravn AS | Real estate | 2006 |
| Aanerud Bakeri Oslo AS | Manufacturing | 2025 |
| Aanerud Entreprenør AS | Construction | 1992 |
| Aanesen Consulting AS | Information & communication | 2026 |
| Aanesrud Holding AS | | 2022 |
| Aanestad Capital AS | Financial services | 2016 |
| Aanestad Holding AS | | 2023 |
| Aangarden Holding AS | Financial services | 2016 |
| Aannestad Holding AS | | 2021 |
| Aanonsen Gaarden Holding AS | Real estate | 2016 |
| Aanonsen Invest AS | Real estate | 1982 |
| Aanstad Enesis AS | Wholesale & retail | 2001 |
| Aarak Capital AS | Real estate | 2020 |
| Aardaltakst AS | Real estate | 2022 |
| Aarekol Forseth Holding AS | | 2025 |
| Aarem Holding AS | Real estate | 2007 |
| Aareon Norge AS | Real estate | 2012 |
| Aares Holding AS | | 2022 |
| Aarheim Invest AS | | 2024 |
| Aarhus & Partners Kapitalforvaltning AS | Professional & scientific | 2014 |
| Aarhus Arkitekter AS | Professional & scientific | 2023 |
| Aarhus Residentials Denmark II AS | Real estate | 2018 |
| Aarnes Eiendom Kurs AS | Education | 2014 |
| Aarnes Eiendoms AS | Real estate | 1990 |
| Aarnseth AS | Health & social care | 2005 |