Giving it one last shot, the federal judge overseeing the Microsoft antitrust trial has appointed a federal mediator in bid to prod the two sides to reach an out-of-court settlement. All previous attempts by Judge Thomas Penfield Jackson to push Microsoft and the government in the direction of a settlement have failed. But both sides welcomed the decision to appoint Richard Posner, the Chief Judge of the US Court of Appeals for the Seventh Circuit in Chicago as mediator. Jackson told the parties of his decision during a Thursday conference in his chambers and the news was announced Friday afternoon. The appointment of Judge Posner, an expert on antitrust who has published extensively -- including works on sexuality and the economics of AIDs, does not mean that a break in the impasse is at hand. Indeed, the current schedule for the trial remains the same and Judge Jackson set February 22 as the court date for oral arguments on the Proposed Rules of Law. That document will be his final determination on whether Microsoft broke federal anti-trust statutes. But considering the sharp rebuke contained in Jackson's findings of fact in the case, some legal experts said Microsoft may have an incentive to settle. In statements since the findings were published November 5, Microsoft officials led by CEO Bill Gates have floated several trial balloons, hinting at the company's willingness to reach a deal. And a spokesman for Microsoft Friday said the company was willing to work with Judge Posner to reach a solution. The equity markets reacted positively to the Posner appointment, sending shares of Microsoft up sharply in after hours trading. Mediators are most commonly brought in as shuttle diplomats between parties who are too far apart in their positions to negotiate, said legal experts. Most often, law professors are tapped for the function. Rarely is a sitting federal judge ever asked to be one. Judge Posner, who has weighed in on other famous antitrust cases, has been described as an inconoclastic and libertarian thinker. He is viewed as a conservative jurist, but one who supports the enforcement of anti-trust laws. What's more, he is not going to need much time to prepare for the case, according to a lawyer close to the government team who said Judge Posner's expertise in economics would help him quickly pierce to the heart of the dispute between Microsoft and the Justice Department."He looks very deep into the economic rationale underlying antitrust," the lawyer said "All his opinions are embedded with economics." There was a related development in the case. Along with the naming of a mediator, Judge Jackson invited Harvard Law Professor Lawrence Lessig to submit a "friend of the court" brief. He also said the United States, the 19 states participating in the lawsuit and Microsoft may designate one expert each to file briefs. Jackson had previously attempted to designate Lessig as a special master to help hear the case. But Microsoft successfully challenged appointment and Lessig's candidacy was withdrawn. The 60-year-old Posner was born in New York City, and grew up in its suburbs. He graduated summa cum laude from Yale College in 1959 with an English degree and graduated first in his class from Harvard Law School where he was president of the Harvard Law Review. After working for several years in the Kennedy and Johnson Administrations, Posner began teaching law at Stanford in 1968 as an associate professor. He became full professor of law at the University of Chicago Law School in 1969. In 1981, he was appointed to the Seventh Circuit. "It would be hard to think of a better guy to appoint as mediator," Silicon Valley antitrust expert and attorney Richard Gray said. He cited Posner's "towering intellect" and thorough knowledge of antitrust law. Robert Lande, a law professor at the University of Maryland, said the mediation referral to Posner has only one clear implication: Microsoft and the DOJ have agreed to try and reach a settlement with a man generally regarded as the leading anti-trust expert in the country. "There is no bigger name in the anti-trust field," he said. It is not unusual for judges to name mediators to work with warring parties while litigation proceeds. The two-track approach is often used to shorten lengthy trials and bring cases to conclusion. "It's a way for both sides to explore ideas without losing face," said Chris Savage, an attorney with Cole Graywid and Braverman in Washington, D.C. "Overall, I'd say it's a good move for both sides, and if they settle, the judge doesn't have to craft a remedy," Soma said. Contributions from Reuters, Lisa M. Bowman and Randy Barrett, Inter@ctive Week What do you think? Tell the Mailroom . And read what others have said.