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| INSTALL AS | 911853914 | LIER |
| INSTALLATØRENE AS | 997781694 | OSLO |
| INSTALLATØREN FREDRIKSTAD AS | 912645177 | FREDRIKSTAD |
| INSTALLATØR PER ØVERLAND AS | 919811714 | PORSGRUNN |
| INSTALLATØR STIG LIND AS | 875971832 | ØKSNES |
| INSTANES AS RÅDGIVENDE INGENIØRER | 934485378 | BERGEN |
| INSTANT VVS AS | 916914067 | LILLESTRØM |
| INSTA RØR&REHAB AS | 930831492 | VESTBY |
| INTEC NORGE ØST AS | 928429032 | OSLO |
| INTERIØRFAGHUSET T. LUND AS | 820500482 | STAVANGER |
| INTERNO BYGG & INTERIØR AS | 922885621 | OSLO |
| INTER RØR AS | 932559331 | SULA |
| INTO ELEKTRO AS | 859028012 | KVINNHERAD |
| INTO RØYR AS | 990977631 | KVINNHERAD |
| INVENT AS | 986464352 | BERGEN |
| IPEC MILJØ AS | 935235618 | BIRKENES |
| IPOA AS | 997039297 | MOSS |
| IPRO BYGGMESTER AS | 928834999 | MOSS |
| IR BETONGARBEID AS | 913194020 | SIRDAL |
| IRBYGG ENTREPRENØR AS | 920405746 | OSLO |
| IRPA AS | 999609384 | HALDEN |
| ISACHSEN ANLEGG AS | 970999507 | DRAMMEN |
| ISAKSEN EIENDOM AS | 984255969 | SØRREISA |
| ISAKSEN NYBYGG OG RESTAURERING | 974987007 | BÅTSFJORD |
| ISBANETEKNIKK AS | 929802667 | HOLMESTRAND |
| ISDALSTØ ANLEGGSERVICE AS | 978654363 | ALVER |
| ISHAVSBYEN ELEKTRO AS | 931596039 | TROMSØ |
| ISOMUR AS | 984571941 | TØNSBERG |
| ISOTAK BYGG AS | 947185039 | BÆRUM |
| Isoteks Miljø AS | 943842353 | GJØVIK |
| ISOVENT AS | 999578837 | KINN |
| ISTAND AS | 932206048 | SUNNFJORD |
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| IVAR BRÅTHEN MEKANISKE AS | 979901925 | STANGE |
| IVAR GRÆNDSEN | 985857075 | OPPDAL |
| IVAR HAUGEN | 980070336 | SUNNDAL |
| IVAR HORSGÅRD | 967986534 | MOLDE |
| IVAR IKS | 871035032 | STAVANGER |
| IVAR ØDEGAARD GRAVING OG TRANSPORT | 926087169 | EIDSVOLL |
| IVAR TANUM ENTREPRENØR AS | 987837969 | DRAMMEN |
| IVCON AS | 927083485 | NESSEBY |
| IVERK AS | 928719863 | HAUGESUND |
| IVEST CONSULT AS | 993456721 | KINN |
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