RealNetworks has filed a $1 billion anti-trust action against Microsoft Corp., charging that the technology giant is attempting to monopolize the digital media space.

RealNetworks has filed a $1 billion anti-trust action against Microsoft Corp., charging that the technology giant is attempting to monopolize the digital media space.

In a suit filed yesterday in federal court in San Jose, Calif., Real alleges that Microsoft has used its power to restrict how PC makers install competing media players. By contrast, it says, Microsoft has tied its Windows Media Player with the Windows operating system, whether users want it or not.

A Microsoft rep could not be reached at deadline.

Real says it has lost significant revenue due to Microsoft's alleged actions. "We believe our business would be substantially larger today if Microsoft were playing by the rules," Real chairman/CEO Rob Glaser says in a statement.

Real is seeking damages in excess of $1 billion and an injunction to prevent alleged "future illegal conduct" by Microsoft. Real expects to spend $12 million in 2004 litigating the case, which the company says could go on for three years.

The suit comes as European regulators investigate possible anti-trust violations involving Microsoft.