 Viacom had distributed the classic CBS library which included the pre-1960 Desilu library, alongside series from Viacom Productions and the Carsey-Werner Productions library (Paramount lost the rights to the latter library in 1997 when Carsey-Werner formed its own in-house distribution unit).PDT also gained syndication rights to series from MTV Networks with the Viacom merger, though these have rarely been seen in syndication.MCA Television and Paramount Domestic Television (PDT) had formed Premier Advertiser Sales, a joint venture created for the sale of advertising for their existing syndicated programs in September 1989.