Washington - The U.S. Department of Justice has announced a formal probe of Yahoo's (NASD: YHOO) proposed online advertising partnership with Google (NASD: GOOG), and will seek documents and information from third party companies with a vested interest in the sector, The Washington Post reported on Wednesday. Google and Yahoo had agreed to voluntarily delay the deal -- which would see Google serve ads against Yahoo search results -- while the Justice Dept. made an informal inquiry, "but a formal investigation signals that the department may have found some cause for concern," The Post reported.

"We're looking at the proposed transaction. We're conducting a civil investigation," Justice Dept. spokeswoman Gina Talamona told CNET News.com, while declining to provide additional details.

Third parties receiving civil investigative demands (CIDs) for documents from the Justice Department are expected to include competitors, major advertisers and potential partners, a source familiar with such investigations told CNET. G

oogle and Yahoo conducted what they later would say was a successful two-week test of the search advertising partnership in April.

Yahoo has said it expects a search ad deal with Google would bring $800 million in revenue in its first year, and provide $250-$450 million in cash flow.

Related Links:
http://snipurl.com/2suup (Washington Post)

http://news.cnet.com/8301-10784_3-9982577-7.html

http://www.justice.gov