Microsoft Corp. (MSFT.O) filed revised documents with the European Commission on Thursday aimed at complying with a landmark antitrust decision from 2004, the European Commission said.

Microsoft met a deadline set by Competition Commissioner Neelie Kroes, but it will be months before it is clear whether the submission is sufficient to avoid a fine that could be as high as 3 million euros ($3.9 million) a day.

The Commission ruled in 2004 that Microsoft had abused its dominant position in the market because Windows, used on more than 95 percent of the world's personal computers, allowed too little interoperability for other software makers.

The Commission's decision, it recalled, required Microsoft to "disclose and license complete and accurate interface documentation which would allow non-Microsoft work group servers to achieve full interoperability with Windows PCs and servers."

"Microsoft has submitted a revised version of the Technical Documentation," the Commission said in a statement.

Asked how long the Commission would take to see whether Microsoft had complied, spokesman Jonathan Todd told a daily briefing: "It's very difficult to put a precise timing on it but I think we're talking months rather than weeks."

The Commission set a deadline of July but delayed it until a court proceeding finished in December, 2004. In July, 2006, the Commission fined Microsoft 280.5 million euros for dragging its feet, on top of a fine of almost 500 million euros in 2004 for its initial violation.

In a statement calling the submission of documents a "milestone," Microsoft said it had completed the review and editing of some 100 documents, which number 8,500 pages.

"We will continue to work closely with the Commission and the (independent) Trustee to ensure that we are in full compliance with every aspect of the Commission's decision," the company said in the statement.

Microsoft says its actions have been lawful and flatly denied the findings of the European Union. It has appealed the decision to Europe's second highest court, the EU's Court of First Instance.

At issue is the low-end market for servers that need to hook up to Windows to manage printers and files.

Novell Netware once led the market but the Commission said Microsoft dealt it a body blow by illegally withholding information it needed to interoperate with Windows.

During that time Microsoft's market share climbed from about one in three to a dominant four out of five low-end servers.

But some businesses can still make use of the documentation.

The Commission said it will allow those businesses to review Microsoft's latest effort "to evaluate whether it contains the necessary information to allow the development of interoperable work group server operating system products."

At the same time, a Monitoring Trustee appointed by the Commission will test the documentation.

If the Commission decides that the documentation is acceptable it will face the question of whether the price Microsoft plans to charge for the protocols is justified.

Microsoft could face further fines if the Commission finds that the price was based on Microsoft's exercise of monopoly power, rather than on the originality of its product.

Another provision of the decision required the software maker to make available a version of Windows without streaming audio-visual software, which Microsoft has done. Customers have shown no interest in that product, however.

Software makers, analysts and investors have keenly watched the long-running battle for its implications for the new Windows operating system Vista, which is due to hit shops in January.

Vista has caused concern for the Commission, prompting Microsoft to make some changes and give data to security software makers for interoperability.

The Commission is focused in particular on the fixed document format offered by Adobe (ADBE.O), and anti-malicious software programmes offered by such companies as McAfee (MFE.N) and Symantec (SYMC.O).