SAN FRANCISCO -- Signaling the gravity of the government's antitrust investigation against Google (GOOG), the Federal Trade Commission has hired a prominent Washington litigator to lead the effort, the first time in at least five years the federal regulatory agency has taken such a step.

Beth Wilkinson, who successfully argued for the government that Oklahoma City bomber Timothy McVeigh be given the death penalty, will start working on the Google investigation Monday, FTC Chairman Jon Leibowitz said Thursday in a meeting with reporters. But he emphasized that her hiring does not mean the government has decided to bring an antitrust charge against the Mountain View company. The government is investigating whether Google has abused its dominance in search to favor its products over those of its smaller competitors.

Still, observers said hiring Wilkinson significantly raises the chances that the FTC will bring the same kind of high-stakes antitrust cases that the Department of Justice brought against Microsoft in the 1990s, when it argued that Microsoft abused its dominance in operating systems to freeze out competitors such as browser maker Netscape. Microsoft avoided being broken up, but is thought to have never regained the same vigor and swagger following its battle with the government.

"This means, to me, that the FTC is quite serious about bringing a case against Google," said Samuel Miller, a San Francisco antitrust lawyer who was recruited by the Justice Department in 1993 to prosecute its first antitrust case against Microsoft. "The antitrust authorities don't bring in outside counsel unless they are very serious about bringing a case."

Wilkinson is an Army veteran and former assistant U.S. attorney who delivered the closing arguments in the case against McVeigh.

In an interview, Wilkinson said she will oversee the FTC's continuing investigation of Google's business practices, and that she would lead the trial team if the FTC files a formal antitrust charge against the Mountain View search giant. Wilkinson is a Washington-based partner in the New York firm Paul, Weiss, Rifkind, Wharton & Garrison.

"I have done a lot of public service in my life, and this gave me an opportunity to do something significant and challenging and important, while maintaining my private practice," she said.

Google, which acknowledged that it was the subject of the FTC probe last June, declined to comment.

"We respect the FTC's process and will be working with them (as we have with other agencies) over the coming months to answer questions about Google and our services," Google Fellow Amit Singhal said in a blog post last year. "It's still unclear exactly what the FTC's concerns are, but we're clear about where we stand. Since the beginning, we have been guided by the idea that, if we focus on the user, all else will follow."

The FTC last year issued a subpoena to the search giant demanding wide-ranging information about Google's business practices, as the five FTC commissioners evaluated whether the company had unlawfully used its monopoly power in search and advertising. Leibowitz did not say when the FTC's investigation would conclude.

For companies like the British product-search company Foundem and others who say that Google has abused its dominance in search to hurt competitors and boost its own products, the hiring of an outside counsel will bring a huge shot of confidence.

"This is not a good day for Google. They are now sitting across the table from somebody who is not going to flinch," said Gary Reback, a prominent antitrust lawyer with the Palo Alto firm of Carr Ferrell who represents a number of Internet companies that have lodged complaints against Google.

Contact Mike Swift at 408-271-3648. Follow him at Twitter.com/swiftstories or Facebook.com/mike.swift3.

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