Microsoft is planning to submit the Office Open XML file format used in its Office suite to the ECMA standards body.  

The move effectively means that Microsoft is opening up the format and ceding some control over the way that Word, Excel and PowerPoint documents are formatted.

This allows third-party developers to start using the layout in their applications without the need for reverse engineering as is currently the case.

Microsoft's move comes at a time when customers, including the State of Massachusetts, are scrutinising Office software over a lack of openness in its document format.

Massachusetts had been eyeing the Open Document Format (ODF) used in OpenOffice as an alternative to the Microsoft standard.

Microsoft's decision to submit the format to ECMA eliminates the objections cited by Massachusetts, according to Rob Helm, director of research at analyst firm Directions on Microsoft.

This now allows Microsoft to bid for government contracts in the state. " ECMA keeps Microsoft Office in the running," Helm told vnunet.com.

Opening up the standard, however, puts an end to the vendor lock-in that required users to purchase Microsoft's Office software if they wanted to read and edit documents created in the suite.

"Microsoft thinks that it can continue to win against OpenOffice on features, " argued Helm. "It does not need a format lock-in to the degree that it might have needed at the time of Office's inception."

A Microsoft spokeswoman told vnunet.com that the company does not want to support ODF because the standard lacks backward compatibility for older Office versions.

She also claimed that ODF is less mature than the Microsoft format and lacks support for accessibility standards and spreadsheet formulas.

ECMA is considered one of the more liberal standards bodies, and is allowing Microsoft to retain ownership of the format.

Other bodies require organisations submitting standards to give up the property, explained Helm.