Microsoft has announced it will offer its Word, Excel and PowerPoint formats as open standards.

The software giant will submit its Office Open XML format to the International Standards Organization (ISO) to be adopted as an international standard in time for the launch of the next version of its Office software suite, it said today.

The decision comes as a group of technology rivals led by IBM and Sun are pushing the OASIS format for office applications called OpenDocument as a global standard format.

It also comes in the wake of a highly publicised decision by the state of Massachusettsto require compliance with OpenDocument for government documents - which effectively forces the phasing out of Microsoft Office and its proprietary format.

Microsoft has been facing increasing pressure from governments and agencies as they have insisted on standards-compliance for their software. Microsoft executives confirmed that the move would help the company win contracts from public authorities that want software based on open standards.

"We have a few barriers [with government contracts]," said Alan Yates, general manager for Microsoft Office. "It will give governments more long-term confidence."

The issue isn't as clear-cut as that however. ISO standards are not the same as open standards. "With an open standard any application can use it," said Louis Suarez-Potts, community manager of OpenOffice.org. "With an ISO standard, it's not quite the same thing. It just means you have a reference for it." If approved, the Office Open XML will see Microsoft grant free licences for its use.

Microsoft has put together a group of companies including Apple, BP, Intel, Toshiba, Barclays Bank, the British Library.and Statoil to make the submission to Geneva-based European Computer Manufacturers Association (ECMA).

The evaluation process is expected to take around a year. Once completed, ECMA will forward a request to the ISO. Microsoft explained that the timing had been chosen to ensure that the XML formats became open standards in time for the launch of Office 12 toward the end of next year.