Microsoft Corp., the world's biggest software maker, has been ordered by a federal court to alter its popular Word software or stop selling the product after it lost its appeal of a $200 million patent-infringement verdict won by a Canadian company.

As of January 11, Microsoft has to stop selling versions of Microsoft Word that infringe on the patent. Word is part of Microsoft's Office software, used by more than 500 million people.

The U.S. federal appeals court jury ruled in favor of Toronto-based i4i Inc., which began the dispute over a patented invention related to customizing extensible markup language, or XML, a way of encoding data to exchange information among programs. Microsoft has called it an obscure functionality.

The judgment included an award of more than $290 million and a permanent injunction, which prohibits Microsoft from selling, offering to sell, importing, or using copies of Word with the infringing technology, the U.S. Court of Appeals for the Federal Circuit ruling said.

Microsoft said it has been working on making the change since August and has put the wheels in motion to remove this little-used feature from our products.

The Redmond, Washington-based company said it will offer a new version with the computer code in question removed. Copies of Word sold before Jan. 11 will not be affected by the court's decision.

Copies of Word 2007 and Office 2007, with this feature removed, will be available for U.S. sale by Jan. 11, and beta versions of Microsoft Word 2010 and Microsoft Office 2010, which are available now for downloading, don't contain the technology covered by the injunction, said company spokesman Kevin Kutz in a statement.

According to the ruling, Microsoft can continue to provide technical support to current Word users. It is prohibited from instructing new users - who buy Word after the deadline - on how to use the custom XML editor or sell copies of Word with the feature.