Microsoft has applied for patents that could prevent competing applications from reading documents created with the latest version of the software giant's Office program.

The company filed similar patent applications in New Zealand and the European Union that cover word processing documents stored in the XML (Extensible Markup Language) format. The proposed patent would cover methods for an application other than the original word processor to access data in the document. The U.S. Patent Office had no record of a similar application.

Microsoft representatives did not immediately respond to requests for comment.

XML-based capabilities have been one of the main selling points for Office 2003, the new version of the market-leading software package. By saving documents as XML files, the new Office will allow back-end computing systems such as corporate databases to retrieve and reuse data from documents. XML support also allows Office to become a client for viewing and manipulating data from Web services and complex enterprise applications, such as customer relationship management software.