| 1 | MET | Meteorological Research Flight | Callsign: Metman, | GB | AVCODES |
| 2 | MET | Meteorological Research Flight | | | ICAO1 |
| 3 | MET | Modesto and Empire Traction Co. | 1/1975-7/2005 | | NAKINA |
| 4 | MET | Modesto and Empire Traction Co. | 1/75-7/2000 | | NRHS |
| 5 | MET | Metropolitan Express Train GmbH | Bad Homburg | D | privat-bahn.de |
| 6 | MET | MODESTO & EMPIRE TRACTION CO. | | | PWRC |
| 7 | MET | Modesto and Empire Traction | | | RSRV |
| 8 | MET | Metropolitan Railway | City: London | GB | TRAFFIC |
| 9 | MET | metronom Eisenbahngesellschaft mbH | | DE | VKM |
| 10 | META | Metzger & Co GmbH | | AT | VKM |
| 11 | METC | Modesto & Empire Traction Co. | 7/1923-10/1966; eliminated 7/1974 | | NAKINA |
| 12 | METC | Modesto & Empire Traction Co. | 4/38-10/66; eliminated 7/74 | | NRHS |
| 13 | METC | MODESTO & EMPIRE TRACTION CO. | | | PWRC |
| 14 | METE | METEOR EXPRESS INC | | | SCAC4 |
| 15 | METG | MOELLER TRUCKING INC | | | SCAC4 |
| 16 | METG | Waggonges. Robert Metzger & Co GmbH | | DE | VKM |
| 17 | METI | MAD EXPRESS TRANSPORTATION INC | | | SCAC4 |
| 18 | METJ | M & E TRUCKING | | | SCAC4 |
| 19 | METK | METRO TRUCKING | | | SCAC4 |
| 20 | METL | MET LOGISTICS INC | | | SCAC4 |
| 21 | METN | METROPOLITAN TRANSPORTATION COMPANY | | | SCAC4 |
| 22 | METO | METRO TRANSPORT LTD | | | SCAC4 |
| 23 | METO | Metropolitan Omnibus | | GB | TRAFFIC |
| 24 | METQ | MEDICAL TECNIQUE INC | | | SCAC4 |
| 25 | METR | metronom Eisenbahngesellschaft mbH | Real: MR | D | TRAFFIC |
| 26 | METRA | Metra | Real: METX, City: Chicago | USA | TRAFFIC |
| 27 | METRA | Metrag AG (Sersa Group) | | CH | VKM |
| 28 | METRO | Metrorail | | ZA | TRAFFIC |
| 29 | METRO | Metro Service A/S | | DK | VKM |
| 30 | METROAPPLE | Metro Apple Express | | USA | TRAFFIC |
| 31 | METS | METRO TRANSPORTATION SERVICES | | | SCAC4 |
| 32 | METU | METAMORFOZA CZ s.r.o. | | CZ | BIC |
| 33 | METU | TOMET LTD | | | SCAC4 |
| 34 | METW | Municipality of East Troy, Wisc. | 1/1975; added 10/1977; eliminated 10/1979; 1/1980-7/2005 | | NAKINA |
| 35 | METW | Municipality of East Troy, Wisc. | 1/75-7/2000 | | NRHS |
| 36 | METW | MUNICIPALITY OF EAST TROY, WISCONSIN | | | PWRC |
| 37 | METW | Municipality of East Troy Wisconsin | | | RSRV |
| 38 | METX | Northeast Illinois Regional Commuter R.R. Corp. | added 10/1996; 7/2000-7/2005 | | NAKINA |
| 39 | METX | The Meader-Atlas Co. | 8/1920-7/1923 | | NAKINA |
| 40 | METX | Northeast Illinois Regional Commuter R.R. Corp. | added 10/96; 7/2000 | | NRHS |
| 41 | METX | *MEADER-ATLAS CO. | | | PWRC |
| 42 | METX | +NORTHEAST ILLINOIS REGIONAL COMMUTER RAILROAD CORP. (METRA) | | | PWRC |
| 43 | METX | Northeast Illinois Regional Commuter Railroad Corporation (Metra) | | | RSRV |
| 44 | METX | NORTHEAST ILLINOIS REGIONAL COMMUTE | | | SCAC4 |
