NEW YORK (Reuters) - The U.S. Justice Department has hired Sandy Litvack, who was its former antitrust chief and Walt Disney Co's (DIS.N: Quote, Profile, Research, Stock Buzz) former vice chairman, to consult on its probe of Google Inc's (GOOG.O: Quote, Profile, Research, Stock Buzz) search advertising deal with Yahoo (YHOO.O: Quote, Profile, Research, Stock Buzz), a source close to the investigation said.
The Justice Department contacted the companies and told them that they were consulting with Litvack -- who was the department's antitrust chief under U.S. President Jimmy Carter -- but had made no decision on whether to challenge the partnership, according to the source.
Yahoo said it was confident that in the end the Justice Department would decide that its deal with Google was legal.
"We have been informed that the Justice Department, as they sometimes do, is seeking advice from an outside consultant, but that we should read nothing into that fact," the search firm said in a statement.
Dow Jones Newswires reported that Litvack had been asked to examine the evidence gathered so far in the federal review of the deal.
According to the Dow Jones story, which cited lawyers close to the review, attorneys have been meeting with witnesses and requesting documents to use in potential litigation to challenge the deal.
"There's no decision," the source close to the investigation told Reuters, referring to a possible challenge of the Google-Yahoo deal.
Yahoo struck the agreement in June with Google, the world's dominant supplier of Web search services, as it sought to shore up its advertising business and ward off pressure to accept a buyout offer by Microsoft Corp (MSFT.O: Quote, Profile, Research, Stock Buzz).
Google spokesman Adam Kovacevich declined to comment on the details of the Justice Department process except to say that the company was cooperating with it.
"While there has been a lot of speculation about this agreement's potential impact on advertisers or ad prices, we think it would be premature for regulators to halt the agreement before we implement it and everyone can judge the actual impact," he said in an email.
(Reporting by Diane Bartz in Washington, Eric Auchard in San Francisco, Sinead Carew in New York; Editing by Gary Hill)