| |||
| Company | Revenue | % of Market | cumu. % |
| AT&T Companies | 38,394 | 53.0 | 53.0 |
| MCI Telecommunications Corp. | 12,924 | 17.8 | 70.8 |
| Sprint Communications Co. | 7,277 | 10.0 | 80.9 |
| LDDS Worldcom | 3,640 | 5.0 | 85.9 |
| Frontier Companies | 1,396 | 1.9 | 87.8 |
| Others | 8,819 | 12.2 | |
| Total long distance carriers | 72,450 | HHI=3,256 | |