| 1 | MTC | Minerva Airlines | IATA: N4, Callsign: Air Minerva, Ceased operations on 25 October 2003 due bankruptcy. IATA designator changed from Q2*, then changed from Q9* | I | AVCODES |
| 2 | MTC | Minerva Airlines | IATA: Q2, Callsign: Air Minerva, IATA designator changed to Q9* | I | AVCODES |
| 3 | MTC | Minerva Airlines | IATA: Q9, Callsign: Air Minerva, IATA designator changed from Q2*, then changed to N4 | I | AVCODES |
| 4 | MTC | Mountain Air Company | IATA: N4 | | ICAO1 |
| 5 | MTC | Boston and Maine Corp. | eliminated 1/1993 | | NAKINA |
| 6 | MTC | Mystic Terminal Co. | 1/1975-1/1980 | | NAKINA |
| 7 | MTC | Mystic Terminal Co. (Boston and Maine Corp.) | 7/1965-10/1966 | | NAKINA |
| 8 | MTC | Mystic Terminal Co. | 1/1941-4/1961 | | NAKINA |
| 9 | MTC | Mystic Terminal Co. (Boston and Maine Corp.) | 4/1938 | | NAKINA |
| 10 | MTC | Mystic Terminal Co. (Boston and Maine R.R.) | 7/1930-7/1936 | | NAKINA |
| 11 | MTC | Mystic Terminal Co. (Boston and Maine Corp.) | Apr-38 | | NRHS |
| 12 | MTC | Mystic Terminal Co. | 1/52-4/61 | | NRHS |
| 13 | MTC | Mystic Terminal Co. (Boston and Maine Corp.) | 7/65-10/66 | | NRHS |
| 14 | MTC | Mystic Terminal Co. | 1/75-1/80 | | NRHS |
| 15 | MTC | Boston and Maine Corp. | eliminated 1/93 | | NRHS |
| 16 | MTC | *(BM)RETIRED 92-10-12 ATP (0467) [BOSTON & MAINE RR; MYSTIC TERMINAL CO.] | | | PWRC |
| 17 | MTC | *MACKINAC TRANSPORTATION COMPANY | | | PWRC |
| 18 | MTC | Mystic Terminal | | | RSRV |
| 19 | MTC | MT CARGO SPEDITION | | SK | VKM |
| 20 | MTCA | MAR-TRANS COMPANY | | | SCAC4 |
| 21 | MTCB | MITTMAN CARRIERS INC | | | SCAC4 |
| 22 | MTCG | MCTIER TRUCKING COMPANY INC | | | SCAC4 |
| 23 | MTCH | MTL CONTAINER LINES | | | SCAC4 |
| 24 | MTCI | MAPLE TANKER CORPORATION | | | SCAC4 |
| 25 | MTCK | MATLACK INC. | | | SCAC1 |
| 26 | MTCK | MILAS TRUCKING COMPANY INC | | | SCAC4 |
| 27 | MTCL | MITCHELL, E STEWART INC | | | SCAC4 |
| 28 | MTCO | Macon Terminal Co. | 1/1975-7/2005 | | NAKINA |
| 29 | MTCO | Macon Terminal Co. | 1/75-7/2000 | | NRHS |
| 30 | MTCO | MACON TERMINAL CO. | | | PWRC |
| 31 | MTCO | Macon Terminal | | | RSRV |
| 32 | MTCO | MICHAELS TRUCKING CORP | | | SCAC4 |
| 33 | MTCQ | MTC BROKERAGE | | | SCAC4 |
| 34 | MTCU | MERLION HOLDINGS PTE LTD | | SGP | BIC |
| 35 | MTCU | MERLION HOLDINGS PTE LTD | | | SCAC4 |
| 36 | MTCW | MYLES TRUCKING INC | | | SCAC4 |
| 37 | MTCX | Mallard Transportation Co. | added 7/1961; 7/1965-7/2005 | | NAKINA |
| 38 | MTCX | Texas Calgary Co. | added 7/1957; 10/1957; eliminated 1/1960 | | NAKINA |
| 39 | MTCX | Texas Calgary Co. | 10/57; eliminated 1/60 | | NRHS |
| 40 | MTCX | Mallard Transportation Co. | 7/65-7/2000 | | NRHS |
| 41 | MTCX | *TEXAS CALGARY CO. | | | PWRC |
| 42 | MTCX | +MALLARD TRANSPORTATION COMPANY | | | PWRC |
| 43 | MTCX | Mallard Transportation | | | RSRV |
| 44 | MTCX | MALLARD TRANSPORTATION COMPANY | | | SCAC4 |
| 45 | MTCZ | *MATLACK TRANSPORTATION CO. | | | PWRC |
| 46 | MTCZ | *MAYFLOWER TRANSIT & STORAGE | | | PWRC |
| 47 | MTCZ | Mayflower Transit and Storage | | | RSRV |
| 48 | MTCZ | MAYFLOWER TRANSIT & STORAGE | | | SCAC4 |
