The European Commission (EC) is to investigate Microsoft’s announcement that it will build support for the OpenDocument Format (ODF) standard into a forthcoming update of Office 2007.

The EC said it had taken note of the proposals, and would be monitoring their progress as part of its ongoing anti-trust investigation into Microsoft and product interoperability.

“The Commission would welcome any step that Microsoft took towards genuine interoperability, more consumer choice and less vendor lock-in,” the EC said in a statement. “The Commission will investigate whether the announced support of ODF in Office leads to better interoperability and allows consumers to process and exchange their documents with the software product of their choice.”

Microsoft yesterday revealed that Office 2007 Service Pack 2 (SP2) will include support for the rival ODF standard, as well as its own Office Open XML document format, which gained ISO approval in April. According to the software giant, the update will let Office 2007 users open, edit and save ODF documents without having to install a converter plug-in tool. Office 2007 SP2 is scheduled for release in the first half of 2009.

“We are committed to providing Office users with greater choice among document formats and enhanced interoperability between those formats and the applications that implement them,” said Chris Capossela, senior vice president for the Microsoft business division.

The move was “cautiously welcomed” by OpenForum Europe, a promoter of open-source software.

“This promise by Microsoft highlights the growing strength of governmental support for ODF and genuinely open interoperability standards,” said OpenForum Europe’s Graham Taylor. “The ODF and open standards communities need to strengthen this support across the world to encourage Microsoft to fulfill their promise to implement ODF in native mode and as a genuine default option for users.”