* German court backs plaintiff Motorola
* Decision has no immediate effect due to U.S. ruling
* EU investigating Motorola's patent enforcement (Adds further details on court ruling)
By Harro Ten Wolde
MANNHEIM, Germany, May 2 (Reuters) - A court in Mannheim ruled on Wednesday that Microsoft infringed Motorola Mobility's patents and ordered Microsoft to remove its popular Xbox 360 gaming consoles and Windows 7 operating system software from the German market.
However, Microsoft said that the ruling did not mean that its products would be taken off retailers' shelves because a U.S. district court in Seattle has granted Microsoft a preliminary injunction against Motorola to prevent the phone maker from enforcing any German court order.
"Motorola is prohibited from acting on today's decision, and our business in Germany will continue as usual while we appeal this decision and pursue the fundamental issue of Motorola's broken promise," Microsoft said in a response to the ruling.
The Mannheim case is related to the larger smartphone patent war being fought by Apple, Microsoft and mobile phone makers who use Google's Android software such as Samsung .
German judge Holger Kircher said on Wednesday Microsoft breached an agreement with Motorola Mobility, which is in the process of being bought by Google, in using certain video-compression software in products including Windows 7 and Xbox.
But following complaints by Microsoft and Apple the EU competition authorities have opened two investigations into whether Motorola has been over-charging for the use of its patents in their rival products.
Technology companies have invested billions of dollars in buying up patent portfolios that they can use defensively or offensively against rivals and spent still more money litigating in the United States and Europe.
Last week a judge for the U.S. International Trade Commission also said Microsoft infringed Motorola Mobility's patents for technology used in the Xbox's wireless internet connection and video compression functions.
However, Wednesday's ruling is also expected to have little immediate impact for Microsoft's wider European distribution operations as it has already moved its regional software distribution centre to the Netherlands from Germany in anticipation of adverse judgments in the patent trial.
Germany has in recent months become a major battleground in the global patent war between makers of mobile phones, tablet computer devices and their operating software as court actions there have proved to be relatively cheap and speedier than in other jurisdictions.
Earlier this year German courts forced Korea's Samsung Electronics to stop selling its Galaxy 10.1 tablet in the country and told Apple Inc to de-activate "push" notification features for some customers in Germany. (Editing by Greg Mahlich)