Microsoft has launched a legal challenge to protect itself from an order by the European Commission to make valuable information about the group’s flagship Windows operating system available to rivals in the open-source community.

The move is the latest twist in the long anti-trust battle between the Commission and the US software group that saw Microsoft punished and fined for breaking European Union competition rules in March last year.

Among other things, the Commission’s ruling against the group forces Microsoft to share sensitive information on Windows contained in so-called communication protocols with rival groups. While Microsoft has accepted this obligation, it refuses to allow competitors to distribute products developed with the help of the protocols under an open-source licence. Microsoft says such a move would allow rivals unfettered access to its intellectual property and is not covered by the March decision.

The Commission said in June that it wanted Microsoft to allow the distribution of software products under an open-source licence, but added that it would not enforce such a move before a ruling by the European Court of First Instance, the EU’s second-highest court. The legal challenge by Microsoft is therefore designed to ensure the court – which is also examining a separate appeal by Microsoft – rules on the issue.

A spokesman for Microsoft said: “This filing is the result of the agreement we reached with the Commission in June to put this particular issue to the Court of First Instance for guidance and to avoid any further delay in the process. We are taking this step so the Court can begin its review of this issue now, given its far-reaching implications for the protection of Microsoft’s intellectual property around the world.”