The companies have been unable to agree since the expiry of a cross-licensing agreement which ended in 2003.
RIM claims that Motorola is using technology over which it has patents in its devices. It also claims that Motorola is demanding excessive licensing fees for technology that RIM wants to use but which is patented by Motorola.
In turn, Motorola is suing RIM for patent infringement. It claims that RIM's technology infringes parts of seven of its patents relating to mobile phone technology.
Motorola said in its court case filing that it seeks a judgment "permanently enjoining [RIM] from further acts of infringement, contributory infringement or inducement of infringement of the asserted patents unless and until licensed under the asserted patents by Plaintiff".
Motorola has asked for unspecified compensatory damages and wants the damages trebled in six of its seven claims. Damages can be trebled in patent infringement cases when the infringements are found to be willful. Motorola has also asked that any trial be conducted in front of a jury.
RIM told Reuters news agency that it had filed a law suit itself alleging patent infringement and claiming that Motorola has raised its patent licensing charges to unreasonable levels.
Motorola's handset business is losing money, and it was recently considering a sell-off of that part of the company, though it has now decided to retain it.
According to Reuters, the RIM law suit claims that Motorola is raising its licensing fees to compensate for losses in the handset business.
Cross-licensing in the mobile phone technology world has become thorny and litigious. Nokia and Qualcomm have been locked in an increasingly bitter patent battle over the use of each other's technology for over two years.
