The Association of National Advertisers announced it sent a letter to the head of the antitrust division of the U.S. Department of Justice, citing its opposition to the controversial Yahoo-Google search advertising deal. The ANA, a powerful group of more than 400 companies that spend more than $100 billion in marketing and commercial advertising, said it conducted a comprehensive and independent analysis of its members and held in-person discussions with both companies before sending the letter to Thomas Barnett, assistant attorney general for the Justice Department's antitrust division.