A Microsoft blogger accidentally leaked an Office Mobile upgrade not due to be released for another couple of weeks.

The upgrade, when it becomes available, should allow Windows Mobile 6.0 users to read Office 2007 documents.

Jason Langridge at Microsoft's Windows Mobile group in the UK, wrote that Office Mobile 6.1 was available and he included a link to the download page. But a Microsoft representative said that the upgrade was supposed to be for internal testing and was only accidentally released to the public.

The new version of Office Mobile is expected to become available very soon, probably within the next two weeks, he said.

The download page, which is no longer accessible, said that the upgrade allows viewing and editing of Word documents and Excel Workbooks and viewing of PowerPoint slides that were created using Office 2007. Office 2007 was released in January and is based on the Open XML format.

Windows Mobile 6.0 devices began hitting the market in the middle of this year but users have been unable to read Office 2007 documents, unless they used a third party software product. DataViz, for example, offers software that lets Windows Mobile 6.0 users read Office 2007 documents.

The upgrade will also enable viewing and extracting from .zip folders, according to Microsoft.