Adobe and Microsoft have fallen out over the "save as PDF" function in Office business software.

Although the two companies came to the table for discussion, Adobe is now threatening legal action against Microsoft for including a "save as PDF" option for free in Office software.

Adobe wants both the "save as PDF" option and the "save as XPS" function removed from the software and offered as a download for a fee. The XPS format is Microsoft's rival to the PDF format.

Microsoft has acquiesced to removing both functions, but does not agreeing with charging a fee for download, as freeware is already available for users to be able to save in both formats.

The question of why some software manufacturers, like OpenOffice, are allowed to include a function for users to save documents as PDFs, while Microsoft is not, has also been raised. Some analysts suspect it is because Adobe sees Microsoft as its biggest rival.