New rumors arose about Research In Motion (RIM)’s upcoming BlackBerry Messenger music service and suggested that the mini subscription plan for the service could cost $5 a month for 50 songs.

Previously, on Thursday, reports about RIM’s late negotiations with major music labels to launch a music streaming service for its BlackBerry devices came in. More reports on Saturday suggested that the service will charge $5 a month for 50 songs.

The BlackBerry Messenger Music Service will arrive as a beta in the U.S., Canada and the UK in early September, before launching in the three regions later this fall. Subscribers, at that time, will not be able to export music to PCs, but they will be able to transfer it to their PlayBook tablet.

The service will also reportedly contain a social aspect that will let subscribers share songs with other BBM Music subscribers. RIM will now compete against pre-existing streaming services such as Pandora, Rdio, Spotify and Rhapsody.

RIM is aiming to use the new subscription music service as a source to revive interest in its BlackBerry Messenger functionality, All Things D reported.