Microsoft 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 Microsoft's Office Open XML (OOXML) format was unripe for ratification by the International Organization for Standardization (ISO), published the results showing Microsoft's win on its Web site.

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.

Supporters of rival Open Document Format (ODF), which is already an ISO standard and widely used, said multiple formats defeated the purpose of having standards and that the result would help Microsoft tighten its grip on computer users.

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.

Microsoft 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 percent of voting national bodies and 75 percent of those known as P-members. A two-thirds majority of the P-members was required.

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.

For additional information visit http://www.ecma-international.org/news/TC45_current_work/ISO_and_IEC_approve_Office_Open_XML.htm.