A South Korean court ruled US software giant Microsoft breached fair competition rules but dismissed suits seeking compensation.

Two local software firms -- Digito.Com and Sanview Technology Inc -- filed suits requesting 30 billion won (24 million dollars) and 10 billion won respectively.

They insisted Microsoft had caused them financial damage by packaging its instant messenger programme and Windows Media Service with the main operating system.

The Seoul District Court decided that the US firm violated anti-trust regulations by abusing its market dominance but rejected the demands for compensation.

It said the plaintiffs lost market share either by lack of price competitiveness or overseas business failure.

"It has not been proven that the damages are linked to Microsoft," it said.

Microsoft in a statement welcomed the court's ruling that its actions did not cause any damage to the plaintiffs.

The company has in recent years been locked in a string of costly disputes with industry rivals in the United States, South Korea and Europe.

South Korea's Fair Trade Commission ruled in 2006 that Microsoft had breached anti-trust laws and ordered it to pay a 32.49-billion-won fine.

In 2007 a European court backed the European Commission's ruling that Microsoft abused its dominant position for personal computer operating systems.