| Petaloudia AS | Bekkestua | 2013 |
| Petax AS | Moss | 2005 |
| Petcom AS | Rykkinn | 2010 |
| Petcom Solutions AS | Saltnes | 2017 |
| Pete Davies Underwater Consultants Ltd | Bn20 9Hr East Sussex | 2009 |
| Peteco Limited | Inverurie Aberdeenshire Ab51 5Jn | 2019 |
| Petek AS | Haslum | 2011 |
| Peter Antonsson Consulting Nuf | Se-452 38 Strømstad | 2023 |
| Peter Hodge International Limited | Insch Ab52 6Pm | 2012 |
| Peter M. Kolderup AS | Bergen | 1981 |
| Peter Mcleod AS | Bergen | 2020 |
| Peter Milne Wellservices Limited | Aberdeenshire Ab31 6Nu | 2012 |
| Peter Opsvik AS | Oslo | 1984 |
| Peter Skagen Invest AS | Bergen | 2005 |
| Peter Smith Engineering Services Limited | Ie-Dublin D22 A2C2 | 2025 |
| Peter Studzinski | De-40595 Duesseldorf | 2018 |
| Peter Wiren AS | Jar | 2018 |
| Peterco AS | Oslo | 2024 |
| Peters & Pihl Holding AS | Oslo | 2011 |
| Peters & Pihl Ventures AS | Oslo | 2014 |
| Petersborg Øwre AS | Ranheim | 2024 |
| Petex AS | Tønsberg | 2005 |
| Petgeo AS | Oslo | 2012 |
| Petim Regnskap 1 AS | Horten | 2018 |
| Petimeter Typo AS | Bergen | 2017 |
| Petimetrica Da | Moelv | 2025 |
| Petit Art AS | Lysaker | 1922 |
| Petit Concept Da | Trondheim | 2005 |
| Petko Drilling & Well Advisory AS | Sandnes | 2025 |
| Petlund Consulting AS | Kristiansand S | 2020 |
| Peto Økonomirådgiving AS | Oslo | 2003 |
| Petra Tech Da | Kristiansand S | 2025 |
| Petrak AS | Kristiansand S | 2022 |
| Petram Consulting LLC | Houston Tx 77060 | 2026 |
| Petraos AS | Straume | 2018 |
| Petras AS | Molde | 2025 |
| Petratech AS | Kristiansand S | 2026 |
| Petrel Group Norway Ltd | Oslo | 1997 |
| Petrell A/S | Trondheim | 1988 |
| Petrex Limited | Aberdeen Grampian Ab 15 Ixu | 2012 |
| Petricore Norway AS | Trondheim | 2017 |
| Petrine Scene AS | Hokkåsen | 2022 |
| Petris Techology SAS | Toulouse 31300 | 2010 |
| Petro AS | Stavanger | 2018 |
| Petro Management Consulting AS | Ålgård | 2013 |
| Petro Safir AS | Oslo | 2022 |
| Petro Teach AS | Trondheim | 2021 |
| Petroadvisor AS | Oslo | 1999 |
| Petroadvisor International AS | Oslo | 2012 |
| Petrocon AS | Stavanger | 2015 |
| Petroconsult AS | Melhus | 2024 |
| Petrofluid AS | Stavanger | 2016 |
| Petroform AS | Sandnes | 2007 |
| Petrofy AS | Fornebu | 2020 |
| Petroil Consulting Ltd | Cheshire Sk4 4Ns | 2017 |
| Petroleum Geo-Services AS | Oslo | 2018 |
| Petroleum Resource Group AS | Oslo | 1996 |
| Petroleum System Consulting AS | Stavanger | 2011 |
| Petroleum Technology Company (UK) Limited | Aberdeen Ab10 6Nw Scotland | 2015 |
| Petrolink Technical Services AS | Stavanger | 2001 |
| Petrolis S.A. | 1227 Carouge Ge | 2013 |
| Petrology AS | Stavanger | 2017 |
| Petronavit AS | Stavanger | 2013 |
| Petronella AS | Oslo | 2007 |
| Petronor E&P Services AS | Oslo | 2018 |
| Petrophysica | Dk-4690 Haslev | 2023 |
| Petroplay AS | Røyneberg | 2017 |
| Petroresources Ltd | Cy-3036 Limmasol | 2026 |
| Petrosam AS | Sandnes | 2006 |
| Petroscience AS | Stavanger | 2012 |
| Petroserv AS | Straume | 2010 |
| Petroserv Limited | Denbighshire Ll18 4Jb Wales | 2020 |
| Petroskills | Tulsa Okl 74153-0448 | 2010 |
| Petrostrat Limited | Ll32 8Fa Conwy England | 2005 |
| Petrotest Bitumen AS | Sandefjord | 2025 |
| Petrotest Fuel & Chemicals AS | Sandefjord | 2025 |
| Petrotrax AS | Trondheim | 2012 |
| Petrowell AS | Paradis | 2005 |
| Petrus Mipco AS | Oslo | 2020 |
| Petrus Veterinærer AS | Oslo | 2020 |
| Petsguest AS | Oslo | 2023 |
| Petster AB Nuf | Oslo | 2017 |
| Petter Aaserud Marketing Services AS | Lommedalen | 2024 |
| Petter Bogen Arkitektkontor AS | Oslo | 2016 |
| Petter Knudsen Design AS | Bergen | 2009 |
| Petter Vabø AS | Hafrsfjord | 1994 |
| Petter Yran AS | Oslo | 1989 |
| PETTERS1 AS | Strømmen | 2023 |
| Pettersen Rådgiving AS | Sandnessjøen | 2024 |
| Petterson Consulting AS | Oslo | 2026 |
| Petuni Invest AS | Drammen | 1999 |
| Petzl Distribution SAS | Fr-38920 Crolles | 2019 |
| Petzl Nordic AB Nuf | Se-164 55 Kista | 2019 |
| Pevatech AS | Valderøya | 2020 |
| Peve AS | Lillehammer | 2007 |
| Pevi AS | Tromsø | 2005 |
| Pevi Holding AS | Kløfta | 2024 |
| Peviab | Se-439 93 Onsala | 2022 |
| Pewe Invest AS | Høvik | 2014 |
| Pewe Miljø AS | Ulefoss | 2019 |