A German court ruled Wednesday that US Internet giant Microsoft can no longer sell its products locally because it infringes patents held by US communications firm Motorola Mobility.
Microsoft said the ruling covers sales of its computer operating system Windows 7 and the Xbox games console but insisted it would have no practical impact.
German customers could still order its products from its distribution centre in the Netherlands, it said.
Microsoft decided to close its German distribution centre in early April, anticipating that the ruling would go against it.
A Microsoft spokesman said the company would also appeal the ruling, given by a tribunal in Mannheim.
High-tech patent disputes have become increasingly common as giants of the industry, especially Apple, Microsoft, Samsung and Motorola, slug it out in the courts to protect their products in a hugely competitive market.
Last month, the US International Trade Commission (ITC) issued a preliminary ruling that Microsoft had infringed Motorola Mobility patents in its Xbox 360 videogame console.
A final ITC ruling is expected later this year which could force the Redmond, Washington-based Microsoft to work out a licensing deal with Motorola or risk having its top-selling videogame console banned from US stores.