Sept. 10 (Bloomberg) -- California Attorney General Jerry Brown disclosed that he is reviewing documents on Google Inc.'s planned partnership with Yahoo! Inc. after a lawmaker asked him to examine whether the deal hurts competition in Web advertising.

The review was disclosed in a letter from Brown's office to California Assemblyman Joel Anderson, a Republican from El Cajon. Eleven state attorneys general are examining the partnership, including Florida and New York, Anderson said in an interview.

The U.S. Justice Department also is scrutinizing the tie-up between the companies, which together handle more than 80 percent of U.S. Web searches. The deal would allow Yahoo to show Mountain View, California-based Google's ads, which fetch higher prices than its own, with the two sharing revenue.

``I'm not saying the deal should be stopped, but it really needs to be vetted,'' Anderson said. ``We are giving an edge to one company to dominate the entire Internet.''

Christine Gasparac, Brown's spokeswoman, wouldn't confirm or deny whether the attorney general is investigating. Yahoo Chief Executive Officer Jerry Yang has said he expects the partnership to generate as much as $800 million a year in sales.

Google, the most popular Web search engine, dropped $4.50 to $414.16 in Nasdaq Stock Market trading today. Sunnyvale, California-based Yahoo advanced 12 cents to $17.70.

California is reviewing the documents through a confidential online document repository made available through the Justice Department, Brown's legislative affairs director, Marc Le Forestier, said in an Aug. 19 letter to Anderson.

The Justice Department hired lawyer Sanford Litvack for a possible antitrust challenge to the partnership. Litvack, the agency's antitrust chief under President Jimmy Carter, will provide advice to the government, Yahoo spokeswoman Tracy Schmaler said yesterday. She didn't immediately return calls for comment today.

To contact the reporter on this story: Karen Gullo in San Francisco at kgullo@bloomberg.net

Last Updated: September 10, 2008 17:05 EDT