Microsoft has been ordered to pay over £175 million for wilfully infringing on a patent by Canadian firm i4i.

The ruling means that Microsoft cannot sell the 2003 and 2007 versions of Word. The patent relates to the use of XML that allows formatting of text and makes files readable across different programs.

I4i supplies Word XML authoring software and claimed that Microsoft infringed its 1998 patent (number 5,787,499), which allows customers to read XML programming language in order to customise document formats.

The company filed a patent in 1998 that outlined a means for ‘manipulating the architecture and the content of a document separately from each other', invoking XML as a means of allowing users to format text documents.

The court found in a jury trial earlier this year that Microsoft had infringed the patent and awarded i4i $200 million (£120m). The latest ruling has ordered Microsoft to pay $40 million (£24m) for the wilful nature of the infringement and interest on the amounts.

The court also prohibited Microsoft from ‘selling, offering to sell, and/or importing in or into the United States' any version of the software that can open custom XML files – including those with file extensions .xml, .docx or .docm.

Microsoft representative Kevin Jutz said in a statement: "We believe the evidence clearly demonstrated that we do not infringe and that the i4i patent is invalid. We will appeal the verdict."