The US Court of Appeals breathed new life into Microsoft’s patent spat with Eolas Wednesday when it reversed part of a lower court ruling in the case and sent it back for a new trial.

The decision reverses a $565m penalty slapped on Microsoft after a district court jury found the software giant infringed an Eolas patent covering a method of opening third party applications within a browser.

In its appeal Microsoft had argued that the original jury had been prevented from considering information on prior art relating to the technology.

Microsoft’s argument clearly washed with the appeals court, which while apparently upholding some parts of the original judgement has sent the case back for a new trial.

Microsoft described the decision as “a clear victory not only for Microsoft, but for Internet users as well” and claimed the ruling was “a clear affirmation of our position.”

Redmond also claimed that it will "now be able to tell the jury the whole story of how this technology was developed and to present evidence that shows that Eolas did not invent this technology, and that it was developed by others, particularly Pei-yuan Wei and his colleagues at O’Reilly and Associates.”"

“The ruling also gives Microsoft the opportunity to present evidence that Eolas knowingly withheld information about Pei-Wei’s invention to the Patent Office,” Microsoft claimed.

Eolas has yet to make a statement on Wednesday’s ruling.

The original decision had prompted concerns well beyond Microsoft, and the World Wide Web Consortium had prompted a US Patents and Trademark Office review of the Eolas patent. ®

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