Microsoft has tried and failed to have Harvard University professor Lawrence Lessig excluded from the US government's antitrust case against it.

In a ruling late yesterday, US District Court Judge Thomas Penfield Jackson dismissed the company's objections to his request that Lessig write a friend-of-the-court brief to help the judge determine whether Microsoft broke antitrust laws.

Jackson announced last month that he was asking Lessig, Microsoft, the US Department of Justice and the 19 states suing the company to submit friend-of-the-court filings on legal issues of their choice. The court order didn't specify Lessig's topic, but the professor has said that he's been asked to address the differences between court rulings on tying together distinct products. Last year, in a related case involving Microsoft, the US Court of Appeals ruled that tying is legal if there are plausible justifications for combining the products, such as helping consumers.

In a motion filed December 9, Microsoft argued that Lessig has formed "strong views" about Microsoft and its role in the software industry, and that those views "will colour whatever he writes." As evidence, Microsoft pointed out that Lessig served as an advisor to Red Hat Centre for Open Source, a non-profit group dedicated to furthering operating systems that compete with Microsoft's products. Microsoft also pointed to a radio interview given by Lessig, in which the law professor compared Microsoft's control over the market for PC operating systems, to the hold AT&T had maintained over the US's telephone system before the telephone company was broken up in 1984.

Lessig has had an on/off relationship with the antitrust case against Microsoft. Jackson had appointed him as a "special master" in a related case, but the Court of Appeals removed him from that post, finding that the case did not warrant such an appointment.

Jackson ruled that this time, his court's request to hear Lessig's views was within its discretion. He wrote: "Professor Lessig appears to the Court to be uniquely qualified to offer advice on a subject few other academics in the country are sufficiently knowledgeable to address at all. And he has, to the court's knowledge, no financial or professional interest in the outcome of the case one way or another."

The judge ended his ruling on a wry note: "The court is confident of its ability to assess Professor Lessig's submission critically, without being affected by any occult bias of which he might be possessed."