OpenOffice supports the Open Document Format
Four countries have appealed against a decision to fast-track the global standardisation of a Microsoft document format, called OpenXML.
Brazil, India, South Africa and Venezuela have complained that there was not enough time given to discuss improvements to the format.
The format is used for spreadsheets, charts, presentations and word processing documents.
Critics claim it is not fully compatible with other document formats.
The ratification of OpenXML would be an important seal of approval for Microsoft, which has long been taken to task for its failure to embrace open standards.
Government bodies would be more likely to adopt the standard if it had an "open" rubber stamp as many are concerned that storing documents in a proprietary format could cause problems for future archiving.
The Office OpenXML format was initially approved by the International Organisation for Standardisation (ISO) in April but will now remain on hold while the appeals are investigated.
This could take several months.
Magna Carta was open source, say campaigners
Microsoft has been working towards a more open way of formatting documents based around the Extensible Markup Language (XML) in response to requests from government customers.
Open standards would help preserve the structure of data in a document, such as a spreadsheet, so that relationships between figures were preserved as they were opened in different programs or used for other purposes.
Microsoft's attempts to have the OpenXML format recognised as interoperable has caused much controversy.
The BSI British Standards voted in favour of adopting it but now faces a legal challenge from the UK's Unix and Open Systems User Group.
At the time of its challenge, UKUUG chairman Alain Williams commented: "The format used for storage of documents will affect our lives for decades to come, and it is imperative that standards such as OpenXML are given a rigorous review rather than being rubber-stamped by BSI.
"Where would we be if the original Magna Carta was unreadable?"