| 1 | GRO | Lineas Aereas Allegro, S.A. de C.V. | IATA: LL, Callsign: Allegro, IATA Prefix: 902, Founded in 1992. Ceased operations during 2004. | MEX | AVCODES |
| 2 | GRO | Allegro | IATA: LL | | ICAO1 |
| 3 | GRO | Lineas Aéreas Allegro | | MEX | TRAFFIC |
| 4 | GROD | PKS Grodzisk Mazowiecki | | PL | TRAFFIC |
| 5 | GRODNO | | City: Grodno | BY | TRAFFIC |
| 6 | GROEGER | Groeger Reisen GmbH | | D | TRAFFIC |
| 7 | GROF | GROE FARM | | | SCAC4 |
| 8 | GROG | GR Omnibus GmbH | | D | TRAFFIC |
| 9 | GROI | Genessee Rail-One Inc. | 7/2005 | | NAKINA |
| 10 | GROI | GENESEE RAIL-ONE, INC. | | | PWRC |
| 11 | GROI | Genesee Rail-One | | | RSRV |
| 12 | GROK | GROSHELL TRANSPORTATION SERVICES IN | | | SCAC4 |
| 13 | GROL | GAROL TRANSPORTATION INC | | | SCAC4 |
| 14 | GRON | GRANT TRANSPORT | | | SCAC4 |
| 15 | GROP | GROWERS TRANSPORT LLC | | | SCAC4 |
| 16 | GROQ | GN ROY | | | SCAC4 |
| 17 | GROR | GROSS, RONALD INC | | | SCAC4 |
| 18 | GROS | GRAVOIS COAL COMPANY | | | SCAC4 |
| 19 | GROT | GROSHELL TRANSPORTATION SERVICES IN | | | SCAC4 |
| 20 | GROU | BOX2HOME | | F | BIC |
| 21 | GROV | S.J. Groves & Sons | | USA | TRAFFIC |
| 22 | GROX | First Union Rail | added 10/1996; 7/2000-7/2005 | | NAKINA |
| 23 | GROX | USL Capital Rail Services | added 4/1994; eliminated 10/1996 | | NAKINA |
| 24 | GROX | U.S. Rail Services, Inc. | added 1/1993; 1/1994; eliminated 4/1994 | | NAKINA |
| 25 | GROX | Chrysler Rail Transportation Corp. | eliminated 1/1993 | | NAKINA |
| 26 | GROX | Growth Nonstock Cooperative, Inc. | added 7/1980; eliminated 10/1988 | | NAKINA |
| 27 | GROX | Georgia Rosin Products Co. | 8/1920-4/1947 | | NAKINA |
| 28 | GROX | Georgia Rosin Products Co. | Apr-38 | | NRHS |
| 29 | GROX | Growth Nonstock Cooperative, Inc. | added 7/80; eliminated 10/88 | | NRHS |
| 30 | GROX | Chrysler Rail Transportation Corp. | eliminated 1/93 | | NRHS |
| 31 | GROX | U.S. Rail Services, Inc. | added 1/93; 1/94; eliminated 4/94 | | NRHS |
| 32 | GROX | USL Capital Rail Services | added 4/94; eliminated 10/96 | | NRHS |
| 33 | GROX | First Union Rail | added 10/96; 7/2000 | | NRHS |
| 34 | GROX | *GEORGIA ROSIN PRODUCTS CO. | | | PWRC |
| 35 | GROX | +FIRST UNION RAIL[(RUSX) USL CAPITAL RAIL SERVICES; CHRYSLER RAIL TRANSPORTAION CORP.; GROWTH NONSTOP COOPERATIVE] | | | PWRC |
| 36 | GROX | Growth Nonstop Cooperative (First Union Rail) | | | RSRV |