Kluge's major move into media was by purchasing stock in the Metropolitan Broadcasting Company in the mid 1950s. The Metropolitan Broadcasting Company was owned by DuMont Laboratories, who originally founded Metropolitan as the DuMont Television Network but decided to change its name in 1955 in the hopes of generating new viewers. Paramount Pictures was a part owner of DuMont Laboratories and persuaded Dr. Allen B. DuMont to allow them to take over the management of the DuMont Network under the new name. The new management lost even more money in this relatively new broadcast medium (television) and shareholders began unloading their stock in the separately run network. Kluge attracted front money and began buying up stock. DuMont sold his shares for about $7,000,000. After gaining control, Kluge renamed the network MetroMedia.
With great success, Kluge began expanding Metromedia with affiliated independent stations. In 1986, Kluge sold the Network to Rupert Murdoch of FOX for a reported $4 billion dollars. The following year, Forbes Magazine placed John Kluge at the top of their list as the richest man in America.
Following the FOX disposal, Kluge's activities have been carried out through a private venture named Metromedia Company in which he is a partner with Stuart Subotnick. Metromedia's more recent activities have included Eastern European, CIS and China telecom/cable/radio ventures through Metromedia International Group and the ill-fated US telecom backbone operation Metromedia Fiber Network.