| 1 | CIX | City Connexion Airlines | IATA: G3, Callsign: Connexion, | RU | AVCODES |
| 2 | CIX | City Connexion Airlines | IATA: G3 | | ICAO1 |
| 3 | CIX | Oxford Paper Co., Inc. | added 10/1958; eliminated 1/1959 | | NAKINA |
| 4 | CIX | Champion-International Co. | added 4/1956; 10/1957; eliminated 10/1958 | | NAKINA |
| 5 | CIX | Champion-International Co. | 10/57; eliminated 10/58 | | NRHS |
| 6 | CIX | Oxford Paper Co., Inc. | added 10/58; eliminated 1/59 | | NRHS |
| 7 | CIX | OXFORD PAPER CO. INC. [CHAMPION-INTERNATIONAL CO.] | | | PWRC |
| 8 | CIXA | CASTILLO TRANSPORT | | | SCAC4 |
| 9 | CIXD | CIARA EXPEDITING INC | | | SCAC3 |
| 10 | CIXF | CRITEX | | | SCAC4 |
| 11 | CIXI | COLUMBUS INDIANA EXPRESS INC | | | SCAC3 |
| 12 | CIXI | COLUMBUS INDIANA EXPRESS INC | | | SCAC4 |
| 13 | CIXL | CON-LEI TRANSPORT LLC | | | SCAC4 |
| 14 | CIXN | COLTRANSPORT INC | | | SCAC4 |
| 15 | CIXO | CI TRANSPORTATION | | | SCAC4 |
| 16 | CIXS | CIRCLE EXPRESS-ALTON (DIV OF ECK MI | | | SCAC3 |
| 17 | CIXT | CRISS INDUSTRIES | | | SCAC4 |
| 18 | CIXX | Calciner Industries, Inc. | 1/1994-7/2005 (not listed) | | NAKINA |
| 19 | CIXX | Calciner Industries, Inc. | 1/94-7/2000 | | NRHS |
| 20 | CIXX | CALCINER INDUSTRIES, INC. | | | PWRC |
| 21 | CIXX | Calciner Industries | | | RSRV |
| 22 | CIXX | CALCINER INDUSTRIES, INC. | | | SCAC4 |
