| Deep C Holding AS | Kristiansund N | 2021 |
| Deep C Solutions AS | Kristiansund N | 2021 |
| Deep Cygnus Operation AS | Fosnavåg | 2013 |
| Deep Sea Drilling Company AS | Kokstad | 2020 |
| Deep Sea Drilling Company I AS | Kokstad | 2013 |
| Deep Sea Drilling Company II KS | Kokstad | 1980 |
| Deep Sea Management AS | Kokstad | 2001 |
| Deep Sea Management International AS | Kokstad | 2022 |
| Deep Sea Rig AS | Kokstad | 2023 |
| Deepocean AS | Haugesund | 1999 |
| Deepocean Corporate AS | Oslo | 2023 |
| Deepocean Group Holding AS | Oslo | 2011 |
| Deepocean Maritime AS | Haugesund | 1986 |
| Deeprock Beheer BV | 4800Gb Breda | 2000 |
| Deeprock CV | 4800 Gb Breda | 2000 |
| Dekar Tomteutvikling AS | Billingstad | 2018 |
| Delmar Systems AS | Straume | 2008 |
| Delta Gold Mining Limited | Oslo | 1999 |
| Dennis Ellison | Beds Lu6 1Aq | 1998 |
| Det Nordnorske Oljeselskap AS | Andenes | 2006 |
| Det Norske Oljeselskap AS | Stavanger | 1986 |
| Dexcrest International Ltd | Herts England | 1995 |
| DF Rental AS | Paradis | 2014 |
| Diatek AS | Klepp Stasjon | 1990 |
| DK Offshore AS | Mandal | 2025 |
| Dlark Ltd | Tyne & Wear Sr1 1Lp | 2016 |
| Dno ASA | Oslo | 1971 |
| Dno Bidco AS | Oslo | 2024 |
| Dno Iraq AS | Oslo | 2005 |
| Dno Norge AS | Stavanger | 2011 |
| Dno Technical Services AS | Oslo | 2014 |
| Dno Yemen AS | Oslo | 2002 |
| Dof Group ASA | Storebø | 2022 |
| Dof Subsea AS | Bergen | 2005 |
| Dof Subsea Atlantic AS | Bergen | 2014 |
| Dof Subsea Chartering AS | Bergen | 2010 |
| Dof Subsea Norway AS | Bergen | 2005 |
| Dof Subsea Rederi AS | Bergen | 2011 |
| Dof Subsea Rederi III AS | Bergen | 2015 |
| Dokkedalen AS | Bagn | 2019 |
| Dolphin Drilling AS | Sandnes | 2022 |
| Dolphin Drilling Offshore AS | Sandnes | 1965 |
| Dolphin Drilling Operations AS | Sandnes | 2017 |
| Dong E&P UK | London Sw1X 7Hy England | 2013 |
| Dovre Stein Da | Dovre | 2007 |
| Dovreskifer AS | Dovre | 2007 |
| Dovreskifer Holding AS | Dovre | 2022 |
| Dovreskifer Invest AS | Dovre | 2022 |
| Dragados Offshore S.A. | 11510 Puerto Real-Cadiz | 2000 |
| Dresser Rand UK Ltd | Stavanger | 1995 |
| DRG Subsea Ltd | Ayrshire Ka12 8Te Scotland | 2013 |
| Drivenes Pukk AS | Vennesla | 2015 |
| Drivetrain Sweden AB | Se-776 28 Hedemora | 1998 |
| Dromnes Grustak AS | Kjørsvikbugen | 2001 |
| DRS Completion Services Limited | Ab15 4Yl Aberdeen | 2010 |
| Drugudal Og Sundset Eiendom AS | Rennebu | 1989 |
| Dsnd Lay Vessel Ltd | Aberdeenshire Ab32 6Jl Scotland | 1995 |
| Dumas Capital AS | Oslo | 2017 |
| Dutch Onshore Offshore Recruit | Stavanger | 1995 |
| Dutch Onshore Offshore Recruit Ment BV | Stavanger | 1995 |
| Dwteknikk AS | Halden | 2003 |
| E Innovation Norge AS | Stavanger | 2012 |
| E Plug AS | Stavanger | 2008 |
| Eclipse Drilling AS | Oslo | 2013 |
| Eco Injeksjon AS | Lunde | 2014 |
| Ecom Investments B.V. | Nl-S Heer Hendrikskinderen 4472Bl | 2022 |
| Edelsplitt AS | Hellvik | 1991 |
| Edeneco Ventures AS | Hvittingfoss | 2024 |
| Egeberg Singel & Pukk AS | Blaker | 2009 |
| Egersund Granite AS | Larvik | 2000 |
| Eide Sandtak AS | Sandane | 1994 |
| Eidesvik Neptun II AS | Bømlo | 2012 |
| Eidesvik Reach AS | Bømlo | 2022 |
| Eikefet Minerals AS | Vikanes | 2024 |
| Eikeland Stein AS | Vikeså | 2009 |
| Eina Pukk AS | Vinstra | 2025 |
| Einar Mosebakken AS | Vågå | 2021 |
| Ekeberg Sandforretning Ans | Aurskog | 2001 |
| Ekornrud Holding AS | Etne | 2005 |
| Elden Pukk Og Maskin AS | Jøa | 2013 |
| Elkania Da | Hauge I Dalane | 2013 |
| Emas-Amc AS | Oslo | 1995 |
| Endrick Survey Services Ltd | Glasgow, Lanarkshire G63 0Rd | 2011 |
| Energold Drilling (Emea) Limited | Kineton Cv35 0Jd | 2020 |
| Energy Minerals AS | Bjørnevatn | 2000 |
| Engebø Rutile and Garnet AS | Naustdal | 2006 |
| Engemoen Grustak AS | Trysil | 2002 |
| Enhanced Drilling AS | Straume | 1997 |
| Enhanced Drilling Holding AS | Straume | 2008 |
| Enhanced Drilling International AS | Straume | 2025 |
| Enhanced Drilling International II AS | Straume | 2025 |
| Enhanced Drilling International III AS | Straume | 2026 |
| Enhanced Well Technologies AS | Straume | 2019 |
| Enhanced Well Technologies Group AS | Straume | 2019 |
| Eniflux AS | Randaberg | 2006 |
| Ensell Well Services Limited | Norfolk Nr316Be | 2014 |
| Equinor Algeria AS | Stavanger | 2003 |
| Equinor Angola AS | Stavanger | 1990 |
| Equinor Angola Block 1/14 AS | Stavanger | 2020 |
| Equinor Angola Block 15 AS | Stavanger | 1997 |