Microsoft hit with antitrust suit over IM

South Korea's largest ISP has filed a $10m won (£4.9m) lawsuit against the world's largest software company, claiming that Microsoft is once again on the wrong side of antitrust laws - this time over instant messaging.

The ISP, Daum Communications, has filed a suit claiming that Redmond's practice of bundling the IM software with Windows XP breaches competition laws. It previously registered a complaint over the same issue with the country's Fair Trade Commission in 2001 but the South Korean FTC hasn't reached a judgement.

Daum is seeking damages on the grounds that it believes that Microsoft is using its dominance to unfairly control the IM market and is hoping that the landmark EU antitrust ruling will lend weight to its complaint.

The company said in its court filing: "Microsoft continues to abuse their market dominance in computer operating systems by bundling the Windows Messenger into their Windows XP software, which apparently is a violation of antitrust law. Daum Communications suffered significant losses with its instant-messaging services due to Microsoft's unlawful actions."

Daum has around 35 million users and says that its share of the country's IM has dropped significantly as a result of Microsoft's dominance.