| Abbreviation | Definition |
|---|---|
| AREC | American River Electric Company |
| AREIT | Australian Real Estate Investment Trust |
| AREP | Affiliated Retail Electric Provider |
| ARESA | Astilleros Reunidos S. A. |
| ARESA | Astilleros REunidos, Societate pe Actiuni |
| ARF | Arch Regional Furs |
| ARG | Affordable Race Graphics |
| ARG | Artie Romero Graphics |
| ARG | Austin Robot Group |
| ARHC | Andean Rural Health Corporation |
| ARI | Alpaca Registry Inc |
| ARI | American Remanufacturers, Inc. |
| ARI | Angus Reid Institute |
| ARI | Associazione Radioamatori Italiani |
| ARI | Automated Research Inc |
| ARIA | Australia Recording Industry Association |
| ARIC | Asia Recovery Information Centre |
| ARIO | Advanced Radiological Incident Operations |
| ARM | Advanced Risc Machines |
| ARM | American Russian Matchmaking |