The Canadian company took Micrsoft to court in 2007 over violations of its patent in Word applications and won the case and got $290 mn in damages last year.

The US court of appeals had upheld a lower court order banning Microsoft from selling its patent-infringing Word processing software from January 11.  In May, the US Patent and Trademark Office also confirmed a patent held by i4i Inc.

Now Microsoft has taken the case to the US apex court confirmed spokesman Kevin Kutz. "Our petition to the Supreme Court focuses on proper standards of proof to determine the validity of a patent, which is a crucial issue for the proper functioning of the patent system,'' he said in a statement.

Responding to Microsoft's move, Michel Vulpe, (right) founder of Toronto-based i4i Inc. and co-inventor of the patent, told the Canadian Press, "We are in this to assert and enforce our patent rights.''

"We see that not only as an issue for us but as an issue all patent holders to have their rights enforced and to make it clear that companies like Microsoft, despite their resources, simply can't walk over small patent holders.''

In its lawsuit filed in March 2007, i4i claimed that the world's biggest software company infringed on a patent granted to it in 1998 for technology that can open documents using the XML programming language and manipulate complex data in electronic documents.

The technology allows users to sort out and manage information by turning complex documents into more accessible databases. i4i claim that Microsoft violated its patent when it created Word 2003 and Word 2007 software.