Microsoft has failed in its bid to subpoena communications from IBM relating to the European Union's anti-trust case against the software vendor. A US District Court judge in New York quashed Microsoft's request on Thursday, joining courts in Massachusetts and California in refusing to support Microsoft's claims.

In an attempt to substantiate its allegations that the European Commission colluded with its rivals over enforcement of the antitrust ruling, Microsoft had asked US courts to order IBM, Sun Microsystems, Novell and Oracle to hand over details of their communications with the Commission and with the monitoring trustee for the case. All three courts have now rejected Microsoft's requests.

Starting Monday, Microsoft will begin its appeal against the 2004 anti-trust ruling at the European Court of First Instance in Luxembourg. The hearing runs through next Friday.

In 2004, the Commission found Microsoft guilty of abusing its dominance in the operating system market for desktop computer systems, and ordered the company to provide details of the communications protocols used by its workgroup server software, among other remedies. The Commission appointed a monitoring trustee - selected from a list proposed by Microsoft - to evaluate the company's compliance with the ruling. His responsibilities include consulting with Microsoft's competitors to gauge the effects of the remedies on the market.

In March, Microsoft accused the Commission and the monitoring trustee of colluding with its rivals and sought to obtain details of their communications from the Commission.

Frustrated by the Commission's refusal on the grounds that its procedural rules made such communications secret, Microsoft sought to obtain the documents from the US offices of the companies concerned.

Judge Colleen McMahon issued an opinion Thursday quashing the request for IBM's documents. A California court rejected Microsoft's request for Sun and Oracle documents last month, and on Monday another court in Massachusetts quashed its attempt to subpoena communications from Novell.

Microsoft has decided not to pursue the California case further. "The writing was clearly on the wall. They're not going to be pursued further," said Brookes.

"Things have moved on in Brussels, and some of the clarification that Microsoft was seeking [from the monitoring trustee] we have received," he said.