| Employer: | Ministry of Transport, Inormation Technology and Communications of the Republic of Bulgaria |
| Beneficiary: | State Enterprise National Railway Infrastructure Company |
| Engineer: | Consortium between TYPSA / SYSTRA/ LOUIS BERGER / TRADEMCO / RUBICON ENGINEERING |
| Consultant: | ADO S.A. / WSP INTERNATIONAL SWEDEN |
| Phase 1 Contractor: | TERNA S.A. |
| Phase 2 Contractor: | ASTALDI S.p.A. |
| Phase 4.1 Contractor: | TERNA S.A. |
| Phase 4.2 Contractor: | PORR/PST HOLDING |
| Phase 4.3 Contractor: | START ENGINEERING |
| Phase 3 Contractor: | OHL ZS a.s. |
| Systems Contractor: | THALES / ALCATEL-LUCENT |