When the FCC imposed its fin-syn rules in 1970, ABC proactively created two companies: Worldvision Enterprises as a syndication distributor, and ABC Circle Films as a production company. However, between the publication and implementation of these regulations, the separation of the network's catalog was made in 1973. The broadcast rights to pre-1973 productions were transferred to Worldvision, which became independent in the same year. The company has been sold several times since Paramount Television acquired it in 1999, and has most recently been absorbed into CBS Television Distribution, a unit of CBS Corporation. Nonetheless, Worldvision sold portions of its catalog, including the Ruby-Spears and Hanna-Barbera libraries, to Turner Broadcasting System in 1990. With Disney's 1996 purchase of ABC, ABC Circle Films was absorbed into Touchstone Television, a Disney subsidiary which in turn was renamed ABC Studios in 2007.