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| MANNIMASKIN AS | 920262023 | OSLO |
| MANTAS BYGGMONTERING AS | 925063231 | BERGEN |
| MANTHEY KULA AS | 913076990 | OSLO |
| MAP ARKITEKTER AS | 992792426 | OSLO |
| MARBERG BYGG- OG TEGNESERVICE | 912054888 | SARPSBORG |
| MARBRE AS | 989822160 | NES |
| MARBRE EIENDOM AS | 985711089 | NES |
| MARCIN PRZEDLACKI | 812221892 | OPPDAL |
| MARCUS - HANDVERKER AS | 924971118 | BÆRUM |
| MARDAL RØR AS | 981406192 | GLOPPEN |
| MARI IGESUND SIVILARKITEKT AS | 922737509 | OSLO |
| MARINA SOLUTIONS AS | 995524252 | SULA |
| MARINE ALUMINIUM AS | 988419486 | KARMØY |
| MARINE METALL AS | 924374462 | FRØYA |
| MARINI CONSULTING AS | 932087537 | LILLESTRØM |
| MARITEX MARINE AS | 916820615 | KLEPP |
| MARITIM SVEISESERVICE AS | 917318964 | TROMSØ |
| MARIUS EGELAND ARKITEKTER AS | 937719701 | LILLESAND |
| MARIUS HANSEBRÅTEN | 981994108 | INDRE ØSTFOLD |
| MARIUSSKIVENES AS | 932497220 | HAMAR |
| MARIUS WAALE AS | 927068362 | LARVIK |
| MARK ARKITEKTER AS | 912613240 | STAVANGER |
| MARKEGÅRD BYGG AS | 929774183 | HEMSEDAL |
| MARKER ANLEGG AS | 894968672 | MARKER |
| MARKUSSEN MASKIN AS | 927426994 | VESTVÅGØY |
| MARLOW ARKITEKTER AS | 993312681 | BÆRUM |
| MARMINA AS | 929208900 | LØRENSKOG |
| MARSELL BYGG AS | 931795414 | HVALER |
| MARSTEEN VVS | 955576799 | OSLO |
| MÅRSTIG BYGG AS | 917962367 | BERGEN |
| MARTA EGGERTSEN BÆREKRAFT, BYPLAN OG ARKITEKTUR AS | 923578668 | ARENDAL |
| MARTEAM. AS | 912219593 | FROGN |
| MARTENS TAKST AS | 915765416 | OSLO |
| MARTHINSEN & DUVHOLT AS | 980416976 | SANDEFJORD |
| MARTIN FREDRIKSEN VVS AS | 992682485 | SYKKYLVEN |
| MARTIN JARNÆS NILSEN AS | 979497660 | NITTEDAL |
| MARTIN J. HOLTER AS | 992687002 | HVALER |
| MARTIN KRISTIANSEN AS | 912805441 | OSLO |
| MARTIN LID TRELAST AS | 957393926 | VOSS |
| MARTIN M BAKKEN AS | 910401017 | ELVERUM |
| MARTIN PRESTEGÅRD AS | 990341354 | BERGEN |
| MARTIN RØNNING AS | 985868506 | ASKER |
| MARTINSEN ANLEGG AS | 911736489 | NORD-AURDAL |
| MARTINSEN BAD & BOLIG AS | 918327967 | OSLO |
| MARTINSEN BETONG AS | 898197832 | MELHUS |
| MARTINSEN & STENSTAD BOLIGENTREPRENØR AS | 991408754 | BÆRUM |
| MASIV BYGG AS | 943612226 | KLEPP |
| MASKIN & EIENDOM AS | 912174115 | TROMSØ |
| MASKINENTREPRENØR EGIL ÅSTAD AS | 834715112 | EIDSVOLL |