He is also known for participating in several TV-commercials for Tuborg and TDC.
On 21 August 1882, C.F. Tietgen took over The International Bell Telephone Company, an American-owned telephone exchange on Lille Kongensgade in Copenhagen, for DKK 200,000 and founded Kjøbenhavns Telefon Aktieselskab, KTS, later Kjøbenhavns Telefon Aktieselskab, KTAS.