AOL has announced that Napster will become the exclusive subscription provider for AOL Music, replacing AOL Music Now, which has about 350,000 paying subscribers.
Existing AOL Music Now customers will have their accounts, including music libraries and playlists, migrated over to Napster unless they choose to opt out.
Napster has hired investment bank UBS to review its options after receiving interest from potential buyers.
The once hugely popular music-downloading service said it was considering whether to sell up or form a joint venture, with potential suitors thought to include mobile operators or media companies such as Viacom.
eMusic has announced plans to launch in all 25 EU countries in a bid to become Europe’s number two music downloading site behind iTunes.