Research In Motion Ltd. is preparing to unveil a music service that will work across the full range of the manufacturers’ Blackberry and other mobile devices, Reuters reported Friday. The Waterloo-based company is negotiating for the rights to sell popular music released by major labels such as Universal Music Group, Sony Music, Warner Music Group and EMI Group. Owners of RIM’s PlayBook tablet currently have access to the online music store run by U.K. company 7Digital, which is partially owned by long-time music distributor HMV. Blackberry smarthone users also have the ability to download music apps like Rhapsody or Slacker from RIM’s app store, but do not have access to a RIM-operated music store akin to Apple Inc.’s iTunes. Blackberry users can also load music and other audio files directly onto their Blackberry from a computer or other device. Citing unnamed sources familiar with the company’s plans, Reuters reported that RIM will announce the new service in early September. The Wall Street Journal also reported Friday that the service will be subscription-based, tied to the BlackBerry Messenger app, and cost about $10 US per month.