Both sides claim infringement in suits filed over the holiday weekend.
BlackBerry-maker Research In Motion and rival Motorola have sued each other over what they say are patent infringements for technology used in their mobile phones.
RIM alleges that Motorola is infringing on the Canadian company's patents and demanding "exorbitant" licensing fees, according to court documents.
The civil action, filed on Saturday in U.S. District Court for the Northern District of Texas, alleges that Motorola infringed on a number of patents held by RIM.
In addition, RIM alleges that Motorola "is demanding exorbitant royalties ... for patents that Motorola claims are essential to various standards for mobile wireless telecommunications and wireless computing that RIM practices."
This includes technology that allows mobile telephone handset users to use Wi-Fi, RIM said.
At the same time, Motorola is refusing to acknowledge or pay royalties for certain patents held by RIM, the BlackBerry-maker said.
Motorola refuted RIM's claims and said it had filed two lawsuits over the weekend against the Canadian company in Texas and Delaware. Motorola is challenging RIM's patents and argues that RIM is infringing on certain Motorola patents.
"We have not yet reviewed the complaint, but based on our understanding of the matter, we believe that their claims are entirely without merit and Motorola intends to vigorously defend itself," Motorola said in a statement e-mailed to Reuters.
Illinois-based Motorola added that it permits others to use its technology if it deems it appropriate and it is properly compensated.
NO AMICABLE AGREEMENT RENEWAL
The current dispute appears to stem from failure to reach an amicable renewal of a 2003 cross-license agreement between Motorola and RIM.
"In this instance, our agreement with RIM expired and we have been unable to reach a suitable agreement going forward," Motorola said.
RIM products targeted in one of the Motorola lawsuits include the BlackBerry 8100, 8300 and 8800 models and BlackBerry Exchange Server software.
None of the allegations from either company has been proved in court.
RIM and Motorola are rivals in the market for mobile phone handsets that can provide several services, including e-mail and Internet access, as well as play music or take photographs.
RIM has been expanding from its mainstay business market into the consumer sector with sleeker handsets such as its multimedia-friendly BlackBerry Pearl model.
Motorola, which has slipped to No. 3 world mobile handset maker behind Samsung and market leader Nokia, has a keyboard on its Q model that is designed for e-mail use.
Last month, Motorola said it was beginning a strategic review that could lead to the separation of its money-losing mobile devices unit. Analysts took that to mean Motorola was shopping around its handset business.
RIM's lawsuit claims that Motorola's response to the "declining fortunes" of its handset business can been seen in dramatic increases in royalties being charged to RIM for certain patented technology.
RIM faced problems of its own a week ago when a three-hour service outage on its network left subscribers across the Americas with spotty or no access to wireless e-mail.
RIM's worldwide subscriber base of about 12 million includes business executives, politicians and professionals who rely on their BlackBerrys to send secure e-mails.