Microsoft's Mac Business Unit (Mac BU) has released beta software for Mac users that allows them to read documents created in Office 2007.

Office 2007 is already available for Windows systems, but the release imposes a new document format called Office Open XML. The new format isn't supported within existing versions of Office for Mac, meaning documents created on Windows machines using the new version of the productivity suite aren't readable by users on other platforms.

The Mac BU assures users that it continues development on Office 2008 for Macs, but meanwhile, Mac users can use the Word Office Open XML Converter, so they can at least read documents created in Office 2007.

Word Office Open XML Converter is a standalone, drag-and-drop Word converter for Office 2004 for Mac and v. X users. The company describes the converter as a "provisional solution until the final, integrated converter is available".

The converter provides read-only access to Office Open XML files and converts Word documents to a Rich Text File (.rtf). It supports both individual and batch file conversion and is available for download now.

Microsoft promises PowerPoint and Excel updates to the converter will be released this summer, made available through AutoUpdate.

The final Office 2004 for Mac converter will offer both read and write functionality, and should ship six to eight weeks after the release of Office 2008 for Mac, the company said.

Writing on his blog, Geoff Price, product unit manager with the Mac BU, said: "Only one-way (read only) conversion is supported in this beta. When sending documents back to colleagues and contacts, we recommend saving to the default .doc format from Mac Word (listed as 'Word document' in the save dialogue). Similarly, we continue to recommend that you advise friends and colleagues who use Office 2007 and collaborate regularly with Mac users to save their documents as a 'Word/Excel/PowerPoint 97-2003 Document' (.doc, .xls, .ppt) to ensure that the files can be shared across platforms while waiting for final availability of Office 2008 for Mac."