Streaming media company alleges the Redmond giant has used its monopolistic position to force out competitors in the field of digital media.

Microsoft is facing yet another lawsuit as RealNetworks alleges the Redmond giant has used its monopolistic position to force out competitors in the field of digital media.

The complaint was filed in federal court in San Jose, California, and alleges that Microsoft "has pursued a broad course of predatory conduct" over a period of years by abusing its monopoly power, resulting in substantial lost revenue and business for RealNetworks.

It has also alleged that Microsoft used its monopoly power to restrict how PC makers install competing media players while forcing every Windows user to take Microsoft’s media player, whether they want it or not.

"While we much prefer competing in the market - as we are doing and have done for nine years - our Board has made a carefully considered business decision to take this action to end Microsoft’s illegal conduct and recover substantial damages on behalf of our shareholders," said Rob Glaser, chairman and CEO in a statement.

Microsoft is already fighting moves by the European Commission to unbundle its media player from Windows. Glaser said in a conference call to reporters that action "will not compensate RealNetworks for the harm caused by Microsoft's conduct."

Microsoft said in a statement that RealNetworks' legal action today was "unfortunate and particularly surprising given the intense competition in the digital media marketplace."