A German court has ruled in Motorola Mobility's favour in a patents dispute with Apple.
The Android smartphone maker had complained that Apple failed to license one of its wireless intellectual properties.
Apple uses the technology in its iPhones and 3G iPads.
Motorola could now try to force Apple to remove the feature from its devices or halt sales in Germany. However, Apple said it intended to appeal.
Motorola said the ruling validated its "efforts to enforce its patents against Apple's infringement".
Apple responded: "We're going to appeal the court's ruling right away. Holiday shoppers in Germany should have no problem finding the iPad or iPhone they want."
If Motorola does decide to pursue an injunction blocking sales of Apple's products the case could result in a clash between the iPad maker and Google - Motorola's shareholders have approved the search giant's takeover of their company and the deal is due to be completed in 2012.
The case relates to Motorola's patent for a "method for performing a countdown function during a mobile-originated transfer for a packet radio system".
Motorola licenses this patent to others on Frand (fair, reasonable and non-discriminatory) terms.
The owner of a Frand-type patent is obligated to license out its technology to third-parties because the invention has been declared to be essential to an industry standard.
Apple had offered to pay a Frand-set fee going forward and was willing to pay a similar rate for past infringements. But it lost the case because it tried to retain the right to contest the validity of the patent with a view to past damages.
It tried to do this because Motorola had defended its right to charge an above-Frand rate for Apple's use of its technology over the past four years. This could have been many times higher than the rate Apple was willing to pay and potentially very expensive.
Motorola will have to post a 100m euro (£85m; $133m) bond if it wishes to enforce a sales injunction against Apple. The cash would cover compensation to Apple if the ruling was later overturned.
Motorola welcomed the ruling.
"We will continue to take all necessary steps to protect our intellectual property, as the company's patent portfolio and licensing agreements with companies both in the US and around the world are critical to our business," said Scott Offer, senior vice-president and general counsel of Motorola Mobility.
"We have been negotiating with Apple and offering them reasonable licensing terms and conditions since 2007, and will continue our efforts to resolve our global patent dispute as soon as practicable."
Patent watchers say it could be years before the case is resolved.
"This is really a given between such large players in high stakes disputes," said Florian Mueller, a patent consultant who revealed the court's verdict on his blog.
"In Germany you get a first ruling by a regional court rather quickly - this litigation started in April this year. Usually between companies of this stature the disputes go to the higher regional court and that could take a couple of years," Mr Mueller told the BBC.
Mr Mueller advises Microsoft and others and has campaigned for patent reform in Europe.
He said Apple could try to revise its products, but noted that Frand-type patents were, by their nature, hard to work around. He added that doing so could run the risk of causing communication problems with the mobile networks' equipment.
Samsung tablet ban
Although Apple is on the receiving end of this lawsuit it has also been very active in the courts suing HTC, Samsung and Motorola among others for claimed patent infringements.
It temporarily managed to have Samsung's tablets banned from sale in Australia, although the restriction was overturned earlier today.
The US International Trade Commission is expected to rule on its dispute with Taiwanese smartphone maker HTC on 14 December. The judgement could lead to shipments of HTC's products being blocked in the US.
Although the targets of Apple's lawsuits are often firms which use Google's Android software, the two firms have avoided suing each other. That is set to change when Google's takeover of Motorola Mobility is completed early next year.
"Google with its pending acquisition will be watching this case with great interest as any victory is an endorsement of Motorola's patent portfolio that it is seeking to acquire," said Ben Cross, director of research at the telecoms consultancy CCS Insight.