The European Union’s Trademark and Design Office, is claiming that Microsoft’s new font for Windows Vista and Office 2007 is a copy of Frutiger Next, a design patented by Linotype, an old German company.

The agency says that Segoe’s letterforms “differ only in minor details” from Frutiger. The three judges in the case noted that Microsoft disputed the documentation of Druckmaschinen’s fonts but “does not contest the claim of the Applicant that they should be considered identical.”

Microsoft applied for at least eight design registrations in January 2004 for different weights of Segoe UI, its user interface font. However, Linotype’s parent company, Heidelberger Druckmaschinen, has appealed against the move.

Jensen Harris, a Microsoft program manager, has written: “We’re not just introducing a new UI in Office [2007] — we’re also introducing a new UI font. It was conceived, designed, and totally optimized for ClearType,” a technology that smooths fonts on LCD screens. It will be turned on by default for the first time in Windows Vista.