Microsoft rolled out a limited beta of its Live Office Workspace file-sharing and collaboration service Monday but will not open it to all comers for at least several weeks, and perhaps months.

The service, which lets users post Microsoft Word, Excel and PowerPoint documents, as well as PDF files to an online storage space, then share them with others, will be available to those who preregistered in October, said Eric Gilmore, the senior product manager for Microsoft Office.

"At the start of the beta, we'll have a private beta period," Gilmore said. "We'll somewhat restrict how many can come on in the next weeks and months until we open it for a public beta." People who preregistered will be admitted on a first-come, first-served basis, Gilmore said, so those who signed up immediately after the service's October 1 announcement will be among the first group given access.

Unlike the efforts of rivals such as Google that are taking shots at Microsoft's Office with online applications, Live Office Workspace is designed for storing and sharing documents, not creating them. The service links to the Windows versions of Office XP, 2003 and 2007 via Save As commands in its applications -- a download add-in is necessary to enable the feature -- and users can designate workspaces as private or shared. A limited set of collaboration tools, including one that lets multiple users add comments to documents stored online, will also be included.

Gilmore played up the service's appeal to consumers and small businesses, but he added that Microsoft isn't targeting larger companies' workers. "I wouldn't say that we don't expect information workers to use this if their organization doesn't have SharePoint or some other collaborative platform," he said. Gilmore then pitched SharePoint Server and Microsoft's other collaborative software, including Groove 2007, as more appropriate for enterprise customers.

Microsoft has, however, signed up several universities and colleges to an early adopter program, including the University of Illinois, the University of Pennsylvania and the University of Washington. Gilmore said that interest from schools exceeded Microsoft's expectations and that the company filled the available slots quickly.

A final release date for Office Live Workspace is "to be determined," Gilmore said, as are details of its pricing structure. The beta, however, is available free of charge, though only to US residents. The service will open to international users early in 2008, and support for languages others than English will be added later next year.

More information about the service and a sign-up form for admission to the beta test pool can be found on Microsoft's Web site.