Denmark's government agencies will be required to handle two competing document format standards, the Open Document Format (ODF) and Microsoft's Open XML, during a one-year test period that will begin next year.

Denmark is requiring both standards for the test period since neither are "fully mature," said Rachid El Mousti, senior adviser for the IT strategy division of Denmark's National IT and Telecom Agency.

A third party will evaluate the results of the tests in the first half of 2009, after which the Danish Parliament will conduct a further assessment, the Ministry of Science and Innovation said.

The government is also requiring that new products bought by the agencies be able to accommodate at least one of the standards. It is also studying how its agencies exchange documents, including their use of converters to change document formats.

Denmark could decide to use one standard, both, or neither of them, depending on market developments, El Mousti said.

Government backing for document formats is seen as significant because it could help promote wider use of the standards in the market. If governments mandate the use of ODF, it could help office suites such as, which use the standard, to compete more effectively with Microsoft's dominant Office suite.

El Mousti said Denmark has felt pressure from supporters of both ODF and Open XML, which was created by Microsoft and is used in Office 2007. Denmark has maintained an open dialog with all vendors, he said.

"In order for us to succeed, not just with open standards ... we of course need to have the vendors with us," El Mousti said.

A Microsoft executive softly chided Denmark's move to mandate standards.

"While I still believe that mandated standards are not an optimal solution for interoperability, this is an important step" in recognising Open XML as a standard, according to a blog posting by Jason Matusow, Microsoft's director for corporate standards.

Denmark does not widely use ODF. Most of its agencies use Microsoft software, and most documents that need to be published are turned into PDFs.

Microsoft has been strongly encouraging governments and organisations to use Open XML, which was approved as a standard by Ecma, a European standards body, in December. Microsoft argues that Open XML has more features than ODF, but some critics say the specification is overly complex.

On Monday, state of Massachusetts put Open XML on a list of standards that could be used for documents in the future, along with ODF.