The Supreme Court on Monday upheld a lower court ruling that Microsoft was not liable to pay damages to a Korean firm for its tie-in sales.

Digito.com, a Korean software company that mainly provides an instant messenger service, filed a lawsuit in 2007 against Microsoft and its Korean branch for abusing its market dominance and bundling its MSN Messenger, an online messenger program, with its computer operating system Windows.

The Korean firm requested 10 billion won ($9.2 million) in damages.

“Even though Microsoft increased its market dominance by bundling its messenger product (with Windows), the lower courts’ rulings are justifiable in which they said it is hard to prove causation between plaintiff’s business failure in the online messenger market and Microsoft’s sales practice,” the court said in its verdict.

In the first and second trials, the lower courts also ruled that, while the world tech giant’s sales practice was obviously illegal, it was hard to prove damages caused to the Korean firm.

In 2007, the Fair Trade Committee fined MS and its Korean branch 27.2 billion won and 53 billion won, respectively, for bundling their instant messenger and Windows Media Service, an audio and video streaming service.

By Kim Young-won (wone0102@heraldcorp.com)