As Google tries to fend off a U.S. probe of its multibillion-dollar search business, it has been quietly adding to its stable of antitrust advisers, which, Reuters has learned, includes a former Microsoft prosecutor.

Jeffrey Blattner, a former U.S. Department of Justice attorney who helped supervise the government's litigation against Microsoft in the 1990s, was one of a handful of Google representatives who attended a briefing for the American Antitrust Institute earlier this year, according to Robert Lande, an AAI senior fellow.

Blattner joins a roster of antitrust heavyweights from outside law firms who are expected to aid the search giant as it engages with the Federal Trade Commission. The agency has launched a formal investigation into Google's search business, the company disclosed last week.

Microsoft waged a two-decade fight with the U.S. Department of Justice and state attorneys general over charges that it abused its monopoly in operating systems to crush competition in other areas.

Microsoft finally settled the matter in 2002, and only last month emerged from government oversight.

Blattner was special counsel for information technology in Justice Department's antitrust division, and now runs his own consulting firm in Washington, D.C., his website says.

AAI issues white papers on antitrust subjects -- for instance, it raised concerns last year about Google's merger with ITA Software Inc. The Justice Department eventually approved that deal, with conditions.

Google representatives met with AAI fellows and staff in January to defend the neutrality of Google's search process, said Randy Stutz, AAI's director of special projects. Google's critics have long complained that Google searches favor Google's own services, and federal investigators and some state attorneys general are reportedly looking into those allegations.

AAI personnel have also been briefed by Microsoft representatives, who laid out the antitrust case against Google, said Lande, who is a professor at University of Baltimore School of Law.

That's the way Washington works, Lande said.

Google did not respond to inquiries about its lawyers, and Blattner declined to comment.

TO SCORCH OR NOT TO SCORCH?

Legal experts are divided on what sort of posture Google is likely to assume as it prepares for what could be the fight of its life with the FTC. Eric Goldman, a professor at Santa Clara University School of Law, notes that while Google must gird for a potentially long and expensive showdown, it also has to work with regulators on any future deals.

That means the company may try to keep the fight from becoming bitter, he said.

Unless Google swears off mergers for a while, I don't think it can use a scorched Earth policy, Goldman said.

Others think the company will try to slow the production of discovery to the FTC.

They're going to scorch the Earth document-wise, and then try to settle for something worthless, said Gary Reback, a well-known antitrust lawyer who once opposed Microsoft and now represents clients adverse to Google.

In dealing with the FTC, Google is expected to continue using its long-time antitrust advisers from the law firm Wilson Sonsini Goodrich & Rosati.

Google also used Cleary Gottlieb Steen & Hamilton in its acquisition of AdMob, the mobile advertising network. In the ITA deal, Google tapped New York-based firm Axinn, Veltrop & Harkrider.

Jonathan Kanter, a Cadwalader, Wickersham & Taft partner who represents Microsoft along with other companies suing Google on antitrust grounds, said Google will likely pair firms together.

I would expect it to be Wilson Sonsini plus one, or two, he said.

(Editing by Steve Orlofsky)

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