| # | Company name | Role | # of projects |
|---|---|---|---|
| 461 | Carol Naughton Associates | Consultancy | 0 |
| 462 | Carpus+Partner AG | Consultancy | 0 |
| 463 | Carroll, Franck & Associates | Consultancy | 1 |
| 464 | Carte Blanche | Consultancy | 0 |
| 465 | Carter-goble Assocs Inc | Consultancy | 0 |
| 466 | Caruana & Associates | Consultancy | 2 |
| 467 | Cascade A & E | Consultancy | 0 |
| 468 | Castles Consulting Engineers Inc. | Consultancy | 5 |
| 469 | Catalyst Consulting Group | Consultancy | 1 |
| 470 | Catella Property Advisors GmbH | Consultancy | 1 |
| 471 | Catella Property Benelux | Consultancy | 1 |
| 472 | Causseaux, Hewett & Walpole, Inc. | Consultancy | 1 |
| 473 | Causseaux, Hewett & Walpole, Inc. | Consultancy | 0 |
| 474 | Causseaux, Hewett & Walpole, Inc. | Consultancy | 0 |
| 475 | CB Richard Ellis A/S | Consultancy | 1 |
| 476 | CBC Byggeadministration A/S | Consultancy | 1 |
| 477 | CBT Companies | Consultancy | 2 |
| 478 | CBT Companies | Consultancy | 7 |
| 479 | CCD Australia Consulting Engineers | Consultancy | 2 |
| 480 | CCI Environmental Services Inc. | Consultancy | 1 |