The European Union's antitrust division on Friday rejected Microsoft Corp.'s allegations that the Competition Commission colluded with rivals.

To back up its position, the commission took a page from Microsoft's playbook, and released several documents outlining the job of its trustee, Neil Barrett, who is in charge of overseeing the Redmond, Wash.-based developer's compliance with a 2004 antitrust ruling.

Earlier this month, Microsoft had called into question Barrett's impartiality and said that he had been in contact with the company's rivals.

Not so, the EU argued.

"The Trustee's contacts with [rival companies] are part of his obligation...and not in any way a form of inappropriate collusion as has been suggested," the commission said in a statement.

The commission cited specific sections of the March 2004 decision against Microsoft to back up its description of Barrett's role in forcing the company to toe the line.

"[The] Decision makes clear that the Trustee, under the supervision of the Commission, has to monitor Microsoft's compliance on his own initiative," the statement went on. "In order to fulfill that proactive role and to form his own, impartial, view on complex technical questions, the Trustee must be in a position to gather views on compliance issues through contacts not only with Microsoft engineers, but also with potential beneficiaries of the remedy." Barrett's findings last year were instrumental in a December official objection that said Microsoft was in violation of the antitrust ruling. Then, the commission announced it would levy a 2 million euro ($2.4 million) per- day fine until Microsoft provided better documentation for the communications protocols required by rivals to build software that could interact with Microsoft's Windows server products.

In answer, Microsoft first said it would release the source code for the protocols, then accused the commission of collaborating with its enemies, and most recently, filed lawsuits in the U.S. to force IBM Corp., Novell Inc., Oracle Corp., and Sun Microsystems Inc. to hand over correspondence between themselves and the EU.

Last month, Microsoft went public with documents it had filed with the commission to bolster its standing in the court of public opinion. The EU's posting of Friday is in some ways a response to that move.

Among the four documents is one that outlines the trustee's responsibilities under the 2004 decision, as well as vitae for Barrett and his two technical advisors, David Parnas and John McDermid.

On Friday, the commission also rejected Microsoft's demand for correspondence between Barrett and the EU, saying that the 2004 ruling specified all communications were to be considered "internal documents," and so, not to be shared.

A hearing on the December non-compliance objection and its fine is planned for later this month in Brussels. Meanwhile, Microsoft will appeal the original antitrust ruling starting in April.