| SIRET | Nom | Nombre copropriétés |
| 38361771900034 | FONCIA LOIRE ATLANTIQUE | 552 |
| 94970422500018 | LEA SYNDIC | 540 |
| 30935834900095 | CABINET THIERRY | 493 |
| 41177707100019 | HEMON-CAMUS | 314 |
| 39882071200055 | CABINET BRAS | 302 |
| 81903818300029 | ROMEFORT IMMOBILIER | 279 |
| 32665016500052 | CABINET JEAN MICHEL LEFEUVRE | 262 |
| 41214482600119 | CITYA NANTES | 197 |
| 82229791700012 | COUDRAY LORRAINE | 197 |
| 79064580800029 | MAISON BSR | 183 |
| 34742156200039 | PATRICK PUGET SA | 172 |
| 30865754300010 | PIVETEAU IMMOBILIER | 151 |
| 34928264000029 | CABINET BOURCY | 143 |
| 39321957100063 | GAALON GUERLESQUIN | 140 |
| 44762160800044 | 4 IMMO | 137 |
| 91197430100010 | LEOPOLD SYNDIC | 124 |
| 85257750100038 | SYMPLICE | 109 |
| 85580046200027 | CIF COOPERATIVE | 107 |
| 91896524500015 | BRAS IMMOBILIER MORBIHAN | 105 |
| 95150146900013 | AMARA GESTION | 99 |
| 32555943300041 | CITYA HOTEL DIEU | 93 |
| 48023607400039 | AVELIM | 93 |
| 48408694700062 | YAOUANC IMMOBILIER | 89 |
| 87380220100012 | CABINET BERTAUD | 72 |
| 50513701800022 | MGEFFRAY IMMOBILIER | 71 |
| 38412129900141 | SQUARE HABITAT ATLANTIQUE VENDEE | 70 |
| 30680960900036 | CHARLES GASCHIGNARD | 68 |
| 52280499600042 | IMMEA | 54 |
| 33890287700020 | CISN SERVICES | 53 |
| 91367990800016 | SYNDIC PARTIE COMMUNE | 53 |
| 82329836900013 | CABINET OLLIERIC | 52 |
| 80190200800029 | BRUNNER SYNDIC RESIDENCES SERVICES | 50 |
| 38077840700029 | MOREL HENRY IMMOBILIER | 48 |
| 31820016900031 | CABINET MOISON | 45 |
| 90126200600017 | CDJ21 | 40 |
| 39748693700014 | CIF SERVICES | 38 |
| 53507816600035 | SEVRE ET LOIRE IMMOBILIER | 38 |
| 83747060800014 | MORAZIN IMMOBILIER | 36 |
| 49435648800010 | TALENTIS IMMO | 28 |
| 98045518200017 | LLICO | 22 |
| 53154278500013 | EURL G.V.I | 15 |
| 84994162000023 | ANGELITA'IMMO | 11 |
| 33855369600091 | FONCIA LOIRE ATLANTIQUE | 6 |
| 91116512400015 | DIX MILLIEMES | 6 |
| 49480022000043 | CABINET GUEMENE | 3 |
| 32955880300097 | GESTION ET PIERRE | 1 |
| 45214576600047 | DEMARE BEAULIEU IMMOBILIER | 1 |