According to a report in the Wall Street Journal , the Department of Justice “has quietly hired one of the nation’s best-known litigators, former Walt Disney Co. vice chairman Sanford Litvack, for a possible antitrust challenge to Google Inc.’s growing power in advertising.””

The Journal states that the hiring of Mr. Litvack’s “is the strongest signal yet that the U.S. is preparing to take court action against Google and its search-advertising deal with Yahoo.”

The Journal specultes that the U.S. may challenge the Google-Yahoo deal alone or look at Google’s conduct in the online advertising business.

Google was down 5.5%,  or $24.30, today in trading.