Office 2004 for Mac users will have to wait four more months to work with documents produced by Office 2007 on Windows and Office 2008 on the Mac, a Microsoft manager said Thursday.

The delay-plagued Open XML converters were slated to show up six to eight weeks after the debut of Office 2008, a schedule that would have put their release by the end of February at the earliest and mid-March at the latest. As recently as last month, Microsoft had confirmed that the converters were on track.

Today, however, Microsoft said they would not appear for months.

"We are pushing back the release of the final Open XML File Format Converter Update to Off