Bulgarian Telecommunications Company AD (BTC)
- Largest telecom operator in Bulgaria. Offers information about the company's services and products, investor data, customer care and e-shop.
- http://www.btc.bg/

Acom
- A privately owned company offering RF and audio equipment for commercial and amateur radio markets. Includes company and product information, product specifications and dealer locations.
- http://www.acom-bg.com/

Estel Systems
- Supplies electronic switching equipment and telecommunication systems.
- http://www.estelsystems.bg/

Pasat Anteny
- Manufactures satellite antennas, offers satellite receivers and components for cable networks.
- http://www.pasat.com/