Rumors have emerged that Viacom -- having missed out on acquiring both MySpace and YouTube -- is now pursuing the music-based social network Last.FM to expand its online and social networking footprint.

According to a post in, Viacom negotiators are in London working on a $450 million deal to acquire the popular site, which combines music-focused blog entries with a user-generated-content Internet radio service.

Last.FM has been gaining momentum with the music industry recently, scoring high-profile content deals with Warner Music Group, IODA and others. Additionally, the site quietly launched a custom radio subscription service in early April for $3 a month.