Microsoft left a two-day antitrust hearing in Brussels Friday claiming it had reached a breakthrough with European regulators in a dispute that may still result in the company being fined up to 2 million euros (US$2.4 million) a day.

But the claim of a breakthrough was exaggerated, according to two other people involved in the closed-door hearing—one person representing rival software companies and a person close to the European Commission, the European Union’s top antitrust authority.

The commission has accused Microsoft of failing to provide adequate technical details about its Windows operating system. The commission ruled two years ago that by withholding this information, Microsoft was stifling competition in the software industry. Microsoft maintains that it has provided the information, which would allow competing makers of server systems to design programs that work as well with PCs running Windows as Microsoft’s own server software.

But in December, professor Neil Barrett, the British computer scientist picked by both Microsoft and the commission to oversee the company’s compliance with the 2004 ruling, dismissed the technical documents on offer as "unusable." As he left the hearing Friday evening, Brad Smith, Microsoft’s top lawyer, told journalists he was "very encouraged when professor Barrett presented his plan to move forward."

Barrett "described in greater specificity than we have ever received before" ways the documentation should be "changed and improved," Smith said. "Certainly for our engineers who had the opportunity to talk directly with professor Barrett during these two days, we finally started to get the kind of engineering guidance that we need," Smith said.

"He described some further details of what should be included and the style in which it should be written. This gives us the start of a real blueprint and it finally answers some of the questions that we have had for some time," he added.

Barrett has been ordered not to talk to journalists, but commission spokesman Jonathan Todd said no new plan was presented. "He is an adviser; he doesn’t make plans," Todd said.

"There was no new plan," said Thomas Vinje, a partner in the Brussels office of law firm Clifford Chance. Vinje represents a software industry trade group called the European Committee for Interoperable Systems, comprising some of Microsoft’s biggest competitors, including Oracle and Sun Microsystems.

Barrett said at the end of the hearing Friday that his initial doubts about the value of Microsoft’s documentation were confirmed, according to Vinje.

"In his final summing up, he talked about ways forward by identifying the problems Microsoft must solve. That’s not a plan," Vinje said.