Napster and satellite radio provider XM Satellite Radio have teamed up to to create an online music service that will enable XM's 4.4 million subscribers to buy music they hear on the paid XM radio service through Napster.

The two plan to jointly launch "XM + Napster," later this year in conjunction with the availability of new XM/MP3 players that let users bookmark songs they hear while listening to the radio for future purchases online.

After the MP3 player is connected to a personal computer, the service will automatically match the marked XM titles with songs in Napster's catalog so that they can be purchased.

Subscribers can also use the XM + Napster service to organize playlists using other songs from personal libraries and transfer these unique playlists to the XM players.

Samsung is one manufacturer looking to include the satellite radio service in its latest batch of MP3 players due to be announced later in the year.