 | MAP ARKITEKTER AS | 992792426 | OSLO |
| MARI IGESUND SIVILARKITEKT AS | 922737509 | OSLO |
| MARSTEEN VVS | 955576799 | OSLO |
| MARTENS TAKST AS | 915765416 | OSLO |
| MARTI AS | 997048172 | OSLO |
| MARTIN KRISTIANSEN AS | 912805441 | OSLO |
| MARTINSEN BAD & BOLIG AS | 918327967 | OSLO |
| MASTERBAD AS | 927209330 | OSLO |
| MAX MAL AS | 998779316 | OSLO |
| MB VVS AS | 929557328 | OSLO |
| MDH ARKITEKTER AS | 995117398 | OSLO |
| MEINICH ARKITEKTER AS | 925974625 | OSLO |
| MELBA VVS AS | 964816565 | OSLO |
| MELLBYE ARKITEKTUR INTERIØR AS | 945844159 | OSLO |
| MELSOM ARKITEKTUR | 931431358 | OSLO |
| MER ARKITEKTUR AS | 939626387 | OSLO |
| MERCUR VVS AS | 915088384 | OSLO |
| MERCUR VVS ENTREPRENØR AS | 920015239 | OSLO |
| MESTA AS | 992804440 | OSLO |
| MESTER BEDRIFTEN BRATFOS RØRSERVICE AS | 924515813 | OSLO |
| MESTER-RØR VVS AS | 996778894 | OSLO |
| META LANDSKAP AS | 926433296 | OSLO |
| METKON AS | 831278242 | OSLO |
| MEYER-EIENDOM AS | 965476296 | OSLO |
| MINH RØRLEGGERSERVICE AS | 983823785 | OSLO |
| MITHASSEL INGENIØR OG RØRLEGGERBEDRIFT AS | 979575319 | OSLO |
| MIVENT AS | 823242522 | OSLO |
| MODERNE BYGGFORNYELSE AS | 979446071 | OSLO |
| MODERNE UTEROM AS | 912682439 | OSLO |
| MODERNE VVS AS | 967478091 | OSLO |
| MODUS ARKITEKTER AS | 998653576 | OSLO |
| MØLLER MUR OG BYGG AS | 963433212 | OSLO |
| MOMENTUM ARKITEKTER AS | 992034904 | OSLO |
| MONIA AS | 918888020 | OSLO |
| MORFEUS AS | 945139579 | OSLO |
| MORFO ARKITEKTER AS | 916637217 | OSLO |
| MORTEN EIDE ARKITEKTER AS | 943783950 | OSLO |
| MOTUM AS | 818709722 | OSLO |
| MPF ENTREPRENØR AS | 985613338 | OSLO |
| MR. PUKK AS | 998740908 | OSLO |
| MRS VVS AS | 917983615 | OSLO |
| MULTICONSULT NORGE AS | 918836519 | OSLO |
| MULTIREHAB AS | 918714227 | OSLO |
| MURERHUSET AS | 912296822 | OSLO |
| MURMESTER 1 OSLO AS | 986403388 | OSLO |
| MURMESTER J LUDVIGSEN AS | 963391714 | OSLO |
| MURMESTER KNUT GUTTORM AS | 979983514 | OSLO |
| MURMESTER OG ENTREPRENØR AS | 918842179 | OSLO |
| MURMESTER OG TAKSTMANN NARVE HELLE AS | 915825710 | OSLO |
| MURMESTRENE SVEEN & CO AS | 930058181 | OSLO |