The advertising deal between Google and Yahoo is not exactly the kind of deal to make marketers happy. Last week, the Association of National Advertisers (ANA) sent a letter to the U.S. Department of Justice (DOJ) posing objections to the Google-Yahoo deal.

According to the group, the Google – Yahoo partnership would control 90 percent of the search advertising inventory, which in their vision, is likely to “diminish competition, increase concentration of market power, limit choices currently available and potentially raise prices to advertisers for high quality, affordable search advertising.”

The Association of National Advertisers (ANA) said they’ve reached this conclusion after conducting a comprehensive analysis of the situation, which included input from its Board members and face-to-face discussions with Google and Yahoo.

On June 12, Yahoo and Google revealed an advertising deal that would allow Google to put some of its search ads on Yahoo pages. The deal is aimed at bringing Google paid search results to some Yahoo search terms. Yahoo expects to get between $250 and $450 million in incremental operation cash flow out of the agreement.

According to the deal, Yahoo will also pay Google up to $250 million in early termination fees if control of the company changes within 24 months, which would be a deterrent for any prospective buyer.

But following the announcement, both lawmakers and marketers began questioning the deal, and the impact it would have on the competition. Yahoo Chief Executive Jerry Yang said at the time that the deal puts Yahoo on a faster track to creating value. However, the partnership came under thorough investigation before being enacted.

Despite fears that the deal will affect competition, the two companies have a somewhat reliable provision in their agreement, which allows other companies to display ads on Yahoo's pages. Thus, it is not an exclusive deal.