FRANKFURT/GENEVA - Microsoft Corp has won a battle to have a key document format adopted as a global standard, improving its chances of winning government contracts and dealing a blow to supporters of a rival format.

The OpenDoc Society, which had argued that Microsoft's Office Open XML (OOXML) format was unripe for ratification by the International Organisation for Standardisation (ISO), published the results showing Microsoft's win on its website.

Microsoft welcomed the decision, which was leaked on Tuesday ahead of an official ISO statement expected on Wednesday, saying it created a 'level playing field' for OOXML to compete with other standards.

Tom Robertson, Microsoft's head of interoperability and standards, said: 'Open XML joins the ranks of PDF, HTML and ODF among the ranks of document formats. I think it makes it easier for governments to offer users choice'.

'The control over the specification now moves into the hands of the global community. This is going to be one of the most, if not the most important document format around the world for years to come,' he added in a phone interview.

James Love, director of Knowledge Economy International, which campaigns for fairer access to knowledge, said: 'We are disappointed.' 'Microsoft's control over document formats has destroyed competition on the desktop, and the fight over OOXML is really a fight over the future of competition and innovation.'

Microsoft, shepherded through a fast-track ISO approval process by European standards organisation Ecma, lost a first ISO vote in September. Under the process, a second vote was allowed after a so-called ballot resolution meeting last month.

In the second voting period that closed on March 29, Microsoft won the approval of 86 per cent of voting national bodies and 75 per cent of those known as P-members. A two-thirds majority of the P-members was required.

Among those voting in favour of OOXML were the United States, Britain, Germany and Japan, according to the OpenDoc Society list. Opponents included China, India and Russia.

The process tested ISO to its limits as national bodies waded through the 6,000 pages of code that define OOXML, then dealt with more than a thousand points of order at the ballot resolution meeting, which was designed to help reach consensus.

ODF has just 860 pages of code, one of the reasons that many experts argue that translation between the two is too incomplete to allow true interoperability - a concept that Microsoft has recently publicly embraced.

Michiel Leenaars, who is on the OpenDoc Society board and chaired the Dutch committee in the first stage of the ISO process, said that OOXML was not ready to be an international standard and that the 15-month ISO process had been too fast.