Facing accusations by Microsoft that it has colluded with the company\u2019s rivals in its ongoing antitrust case, the European Commission has hit back. On Friday, the commission released a confidential agreement with the company that, it says, proves that it has acted properly. Last Thursday, Microsoft filed a formal complaint against the commission, saying that the body was failing to act as a fair and independent regulator in the antitrust case. The company said that the commission encouraged Microsoft rivals such as Sun Microsystems and IBM to lobby an independent computer expert, who is supposed to advise the commission on whether Microsoft is complying with the commission\u2019s 2004 antitrust ruling, to take an anti-Microsoft line. On Friday, the commission published a document that details the mandate of the expert, the so-called monitoring trustee. The commission and Microsoft reached an agreement on the mandate last October. A commission spokesman said the document showed that it was perfectly normal for the trustee, U.K. computer scientist Professor Neil Barrett, to have contacts with rival firms. "It is part of the obligation of the trustee to proactively make contact with third parties and discuss what information they require to make interoperable products," said Jonathan Todd, spokesman for Competition Commissioner Neelie Kroes.In addition, Todd said that the document, which has been published on the commission\u2019s website, "clarifies that communications [between the trustee and the commission] are classified as internal documents" and as such are not accessible to Microsoft.Todd added that the trustee was a "leading and very well regarded computer expert who was recommended by Microsoft."Todd said that the decision to publish the document detailing the trustee\u2019s mandate had been taken following consultations with Microsoft that could have prevented its release but did not do so.Todd said the commission would not normally publish this type of document but had decided to do so in response to allegations that the trustee had been acting in an "inappropriate manner."Microsoft wants the commission to release correspondence between rival companies, the trustee and the commission\u2019s internal experts that, the company says, would provide evidence of the commission\u2019s bias.A Microsoft spokesman denied that the document allowed the commission to deny the company access to the correspondence between the trustee, the commission and the company\u2019s rivals. "Nothing in the decision published today authorizes the commission to sidestep the file access and other due process guarantees to which all companies are entitled under European law and which have been neglected in this case," said Microsoft spokesman Tom Brookes.A 2004 commission ruling found Microsoft guilty of exploiting the dominance of its Windows operating system in the desktop PC sector to gain market share for bundled products. As part of the ruling, the commission ordered Microsoft to release a version of its OS without Windows Media Player and provide documentation that would allow rival products to interoperate with its workgroup server software.The commission argues that Microsoft has not yet provided the necessary documentation to prove it is complying with the ruling and is threatening to fine the company \u20ac2 million (US$2.4 million) a day unless it complies.Microsoft says it has done everything it can to comply, including offering access to the relevant source code in Windows. It will present its arguments at a hearing in Brussels at the end of March.-Simon Taylor, IDG News ServiceFor related news coverage, read Microsoft Source Code Offer is \u2018Poisoned Honey Pot,\u2019 Say Rivals\u00a0and MS: EU Riding \u2018Roughshod\u2019 Over Its Defense.Keep checking in at our CIO News Alerts page for updated news coverage.