| SIAS AS | 976879406 | TØNSBERG |
| SIEKACZ VAKTMESTER SERVICE AS | 998638437 | LARVIK |
| SIEMENS AS | 923009108 | OSLO |
| SI ENTREPRENØR AS | 827610372 | OSLO |
| SIERO AS | 922168245 | TRONDHEIM |
| SIFAB BYGG AS | 921413734 | SANDNES |
| SIGDAL ANLEGGSSERVICE AS | 920776396 | SIGDAL |
| SIGFRED BENTZEN & SØNN AS | 910462105 | OSLO |
| SIG HALVORSEN AS | 976700376 | SANDNES |
| SIGMUND FAGERLI | 977179335 | ORKLAND |
| SIGMUND HVILA AS | 980669599 | SIGDAL |
| SIGMUND LOTHE AS | 939507213 | SOLA |
| SIGNAL BYGG AS | 927519720 | SARPSBORG |
| SIGN AS | 977227984 | NAMSOS |
| SIGN CONSULT NORWAY AS | 966597879 | ULLENSAKER |
| SIGNEX AS | 980833143 | OSLO |
| SIGSO BYGG AS | 927018853 | HUSTADVIKA |
| SIGURD FOSSLI AS | 911791595 | ASKER |
| SIGURD FURULUND MASKIN AS | 976950275 | ULLENSAKER |
| SIGURD OG OLA GRIMSTAD AS | 971587229 | GAUSDAL |
| SIGURD OPHEIM AS | 884492122 | BERGEN |
| SIGVE HAMRE MASKIN AS | 931453734 | SANDNES |
| SIKVELAND STÅLE NOROLV | 970311157 | TIME |
| SILJAN BYGG AS | 828490192 | OSLO |
| SILJUBERGSÅSEN HÅNDVERKSTJENESTER | 928848094 | ELVERUM |
| SILKOSET BYGG AS | 983928447 | ELVERUM |
| SILSAND MASKIN AS | 974520737 | SENJA |
| SIMBRA RÅDGIVNING AS | 922618585 | HAMAR |
| SIMEN HØGSTAD MASKINENTREPRENØR AS | 922796459 | MIDT-TELEMARK |
| SIMEN KVISSEL ENTREPRENØR | 997248430 | ELVERUM |
| SIMEX ELEKTRO AS | 917356181 | STAVANGER |
| SIMEX RØR AS | 917718393 | STAVANGER |
| SIMM AS | 987872756 | BERGEN |
| SIMONA STADPIPE AS | 981928652 | STAD |
| SIMONSEN MASKIN AS | 960292154 | BODØ |
| SIMTEK VVS LTD | 991400168 | OSLO |
| SIMUNDSET & GROEGGEN DRIFT AS | 931676059 | ORKLAND |
| SINDRE MYHRSVEEN HOLDING AS | 820641752 | RINGEBU |
| SINDSEN MASKIN AS | 913673611 | HOLMESTRAND |
| SINGH RØR AS | 925946877 | LILLESTRØM |
| SINUS AS | 984548621 | ALSTAHAUG |
| SINUS BODØ AS | 983156207 | BODØ |
| SINUS BRØNNØYSUND AS | 953343339 | BRØNNØY |
| SINUS ELEKTRO AS | 989059335 | SANDNES |
| SINUS MOSJØEN AS | 996301559 | VEFSN |
| SIO RØR AS | 922053278 | KRAGERØ |
| SIQVELAND & TØNNESSEN AS | 913727304 | TIME |
| SIRDAL BYGG AS | 981906136 | SIRDAL |
| SIRDAL HANDLAFT AS | 877545512 | SIRDAL |
| SIRDAL HYTTER OG HUS AS | 984669712 | SIRDAL |