Microsoft is set to release hundreds of pieces of technical data relating to its Windows operating system as part of a proposed antitrust settlement, although the legal wrangle over its market dominance is not yet over, the company said yesterday.

The disclosure of more of Microsoft's previously secret Windows-related computer code and internal operating rules could help the company's competitors write programmes that run on Windows just as well as its own products do.

Mr Brad Smith, Microsoft's general counsel, said yesterday that Microsoft was "obligated as a company to continue to move forward to meet our obligations under the agreement, even as we are waiting for a final decision".

The data will be released this month, with some available online at no charge, and the rest designed for servers requiring a licensing fee.

The root of the antitrust case lay in critics' claims that the software company unfairly dominated the market because its operating system was virtually universal.

Microsoft was therefore able to promote its own Windows-compatible software while withholding technical data that would enable others to make compatible software, critics charged.

Microsoft reached the proposed settlement with the US Justice Department last year, after an appeals court threw out an earlier ruling that the firm be broken up.