| AB Trepleie AS | Agriculture & fishing | 1996 |
| Abbon AS | Professional & scientific | 2014 |
| Aida Elektro AS | Construction | 1998 |
| Aktiv Ryddecentral AS | Water & waste | 2011 |
| Alfa Software AS | Information & communication | 2025 |
| Amandator AS | Wholesale & retail | 1992 |
| Arba AS | Health & social care | 1974 |
| Arba Inkludering AS | Health & social care | 2017 |
| Arba Leverer AS | Administrative & support | 2023 |
| Arnesen AS | Construction | 1986 |
| Arnesen Frøhaug Betongentreprenør AS | Construction | 2025 |
| Arnesen Frøhaug Holding AS | Construction | 2024 |
| Arnesen Guriby - Agk Eiendom AS | Real estate | 1996 |
| Artisan Bakery AS | Manufacturing | 2025 |
| AS Bærum Ishall | Arts & recreation | 1991 |
| Ascaro AS | Manufacturing | 1965 |
| Aschim AS | Real estate | 2005 |
| Atria Norge AS | Wholesale & retail | 2024 |
| Audiocenteret AS | Wholesale & retail | 2016 |
| Auto-Rep AS | Other services | 1967 |
| Autoclima AS | Wholesale & retail | 2003 |
| Autoco Bærum AS | Wholesale & retail | 1989 |
| Autotakst AS | Professional & scientific | 2015 |
| Autovia AS | Wholesale & retail | 2006 |
| Autoville Eiendom AS | Real estate | 1986 |
| Autoville Holding AS | Real estate | 2017 |
| Avenue Brasil AS | Real estate | 2006 |
| Avenue Invest AS | Real estate | 1984 |
| Azimuth Invest Da | Professional & scientific | 2007 |
| B&G Regnskap AS | Professional & scientific | 2019 |
| Bacco AS | Manufacturing | 2013 |
| Bake Me Up AS | Wholesale & retail | 2020 |
| Bakke Bulktransport AS | Transport & logistics | 1995 |
| Barn Til Bords AS | Hospitality | 2012 |
| Basecamp Reklamebyrå AS | Professional & scientific | 2000 |
| BBV Holding AS | Construction | 2023 |
| Bel-Air Bidco AS | Administrative & support | 2022 |
| Bel-Air Holdco AS | Administrative & support | 2022 |
| Berg Auto AS | Wholesale & retail | 2021 |
| Berg Auto Holding AS | | 2021 |
| Bertel O Steen Asker Og Bærum AS | Other services | 2002 |
| Bilsenteret AS | Other services | 1976 |
| Bilsenteret Stryn AS | Wholesale & retail | 1999 |
| Bjerke Eiendom AS | Other services | 1989 |
| Boneo AS | Real estate | 2018 |
| Brenden & Co Gjenvinning AS | Water & waste | 2024 |
| Broen Næringsbygg AS | Real estate | 2008 |
| Bruun Eiendom AS | Real estate | 2018 |
| Bruun Eiendom Holding AS | Real estate | 1969 |
| Bruun Holdings AS | Financial services | 2010 |
| Brynville AS | Real estate | 2006 |
| Brødrene Børresen Fliser AS | Wholesale & retail | 2012 |
| Brødrene Topaas AS | Construction | 2014 |
| Btlarsen Holding AS | | 2020 |
| BWF AS | Real estate | 2012 |
| Bygg 87 AS | Construction | 2024 |
| Byggkonsulentene-Øst AS | Professional & scientific | 2015 |
| Byggmesterene Olsen Og Lindahl AS | Construction | 2003 |
| Bærum Auto Invest AS | Wholesale & retail | 1999 |
| Bærum Autolakkering AS | Other services | 1997 |
| Bærum Biloppretting AS | Other services | 1982 |
| Bærum Bilverksted AS | Other services | 2020 |
| Bærum Blikk Og Ventilasjon AS | Construction | 1990 |
| Bærum Byggmontering AS | Construction | 1994 |
| Bærum Forsikringssenter AS | Financial services | 2013 |
| Bærum Gjenvinning AS | Water & waste | 1986 |
| Bærum Golfsenter AS | Administrative & support | 2013 |
| Bærum Rørleggerbedrift AS | Construction | 1960 |
| Bærumsnett AS | Construction | 2025 |
| Cabo Golf Resort AS | Real estate | 2016 |
| Coh Invest AS | | 2022 |
| Comex AS | Professional & scientific | 2003 |
| Crown Venture AS | Transport & logistics | 2010 |
| Deko Invent AS | Construction | 2008 |
| Delpi AS | Professional & scientific | 2019 |
| Doma Eiendom AS | Real estate | 2016 |
| Dovre Auto AS | Wholesale & retail | 2024 |
| Dør & Vindu Oslo AS | Wholesale & retail | 2007 |
| Effekta AS | Wholesale & retail | 1990 |
| Eksos Partner AS | Other services | 2011 |
| El-Verkstedet AS | Manufacturing | 2015 |
| Elektroentreprenør Guriby AS | Construction | 1987 |
| Enerklima AS | Professional & scientific | 2009 |
| Eneroptima AS | Information & communication | 2024 |
| Favuseal AS | Wholesale & retail | 2005 |
| Favuseal Hvac AS | Professional & scientific | 2022 |
| Favuseal Steel AS | Professional & scientific | 2013 |
| Favuseal Wire & Cable AS | Manufacturing | 2015 |
| Filippa AS | | 2016 |
| Fink & Henning Bygg AS | Construction | 2011 |
| Fitnation AS | Health & social care | 2016 |
| Fornebu Autotakst AS | Professional & scientific | 2012 |
| Fortem AS | Administrative & support | 2019 |
| Foss Entreprenør AS | Construction | 2017 |
| Franzefoss AS | Water & waste | 2003 |
| Franzefoss Bruk A/S | Manufacturing | 1936 |
| Franzefoss Eiendom AS | Real estate | 2023 |
| Franzefoss Energi AS | Energy | 2023 |
| Franzefoss Gjenvinning AS | Water & waste | 1995 |
| Franzefoss Minerals AS | Mining & quarrying | 2000 |