The US Supreme Court ruled against Microsoft in its high profile appeal of a $290m patent case verdict against Canadian company i4i.

The verdict brings to an end a long-lasting legal battle which saw i4i sue Microsoft in 2007, saying the technology which allows text manipulation in the Microsoft Word application belonged to i4i. According to i4i it was this feature that improved document contents in Microsoft Word 2003 and Word 2007.

Microsoft has been ordered to pay the full amount and to cease selling versions of Word with infringing technology.

The fine imposed by the appeals court is the largest fine to date for a patent infringement case.