CBS said in a statement that the online service has more than 15 million active users in more than 200 countries and would fit well with its plans to attract younger viewers and transform it from a content company to an audience company.
The Last team will continue to run the online network under the terms of the deal and work with CBS to apply its community-building and technology expertise to extend CBS businesses online, the media conglomerate said.
Last has earned glowing praise for its system, which recommends songs by tracking listeners' music-playing habits and linking them to fans with similar tastes.
The group, based in London, has also recently signed deals with music majors Warner Music Group and EMI Group to play their music. Last launched in 2002 and has its largest concentration of users in the United States, Britain, Germany, Poland, Brazil and Japan.
"Last.fm is one of the most well-established, fastest-growing online community networks out there," said Leslie Moonves, President and Chief executive of CBS.
"Their demographics play perfectly to CBS' goal to attract younger viewers and listeners across our businesses," Moonves said. "Last.fm adds a terrific interactive extension to all of our properties and also is a huge step in CBS Corporation's overall strategy of expanding our reach online to transition from a content company into an audience company."