| Abbreviation | Definition |
|---|---|
| UH | U S Home Corporation |
| UHS | Universal Health Services, Inc. |
| UHT | Universal Health Realty Income Fund |
| UIC | United Industrial Corporation |
| UIF | USLife Income Fund, Inc. |
| UIL | United Illumination Company |
| UILPA | United Illumination Company Preferred A |
| UIS | UNISYS Corporation |
| UK | Union Carbide Corporation (delisted) |
| UL | Unilever, PLC. |
| UM | Utah Medical Products, Inc. |
| UMG | MediaOne Group, Inc. |
| UMGPA | MediaOne Group, Inc. Financial Trust I |
| UMGPB | MediaOne Group, Inc. Financial Trust II |
| UMGPC | MediaOne Group, Inc. Financial Trust III |
| UMGPX | MediaOne Group, Inc. Financing A |
| UMGPY | MediaOne Group, Inc. Financing B |
| UMX | MediaOne Group, Inc. |
| UN | Unilever, N. V. |
| UNA | UNova, Inc. |