| Abbreviation | Definition |
|---|---|
| UNB | Union Bankshares Inc. |
| UND | UnUmProvident Corporation |
| UNF | Unifirst Corporation |
| UNH | United Health Group Inc. (formerly United Healthcare Corporation) |
| UNM | UnUmProvident Corporation |
| UNO | Uno Restaurant Corporation |
| UNP | Union Pacific Corporation |
| UNR | Supermercados Unimarc, S. A. |
| UNS | Unisource Energy Corporation |
| UNT | Unit Corporation |
| UPC | Union Planters Corporation |
| UPK | United Park City Mines Company |
| UPM | U P M - Kymmene Corporation |
| UPR | Union Pacific Resources Group, Inc. |
| UPS | United Parcel Service, Inc. |
| URB | Urban Shopping Centers, Inc. |
| URI | United Rentals, Inc. |
| URS | U R S Corporation |
| USA | Liberty All Star Equity Fund |
| USB | U S Bancorp of Delaware |