The ongoing investigation conducted by the U.S. Department of Justice will further delay the controversial advertising deal between Google and Yahoo.

Google’s officials explained that ever since the deal was announced back in June, both companies knew that the verification process will be carried on over a period of several months, as there are many details that must be checked. "As we are still in conversation with the Department of Justice, we have agreed to a brief delay in implementing the agreement while those discussions continue."

Considering the fact that the two companies are the search market’s biggest players, critics believe that the deal will cause major damage to competition and also lead to higher prices. This rumor was addressed by Tim Armstrong, president of advertising and commerce for Google in North America, in one of his recent blog posts. "Neither Google nor Yahoo set ad prices. Ads are priced by an auction where an advertiser only bids what an ad is worth to them," he explained.

The deal will allow Google to sell advertising for some of Yahoo's online advertising space, and considering Google's 63 percent web-search market share and Yahoo’s 19.6 percent, the impact should be significant.

To further support its cause, Google launched a Web site which provides information about the deal’s progress and talks about the benefits that advertisers could receive once the deal will be approved.

The Department of Justice will continue its antitrust investigation into the partnership and a final conclusion should be released over the next several weeks.