• by Joe Mandese  @mp_joemandese, November 21, 2007

At a time when new media stock values are reaching new heights, the shares of Madison Avenue's big publicly traded ad agency holding companies have taken it on the chin in a major market correction. Shares of Aegis Group, Interpublic, Omnicom, Publicis and WPP have all fallen to or near the low end of their 52-week trading range due to mounting concerns over a potential U.S. economic recession, and downgrades from various Wall Street analysts.

Shares of Omnicom, the world's largest advertising services company, and the parent of OMD, PHD, BBDO, DDB, and TBWA/Chiat/Day, closed the day of trading on Tuesday at $47.46, near its 52-week low of $45.82, and off its high of $55.45. Banc of America recently downgraded shares of Omnicom's stock to a "sell" recommendation, and Interpublic fell to "neutral" from "buy."

Shares of Interpublic stock closed Tuesday at $9.03, near their 52-week low of $8.69, and of their high of $13.94.

Shares of WPP Group, the world's largest buyer of media and the parent of MedicaCom, Mediaedge:cia, MindShare, Ogilvy & Mather and JWT, closed Tuesday at $60.41, near their low of $59.31, and off their high of $78.62.

Shares of Publicis Groupe, the parent of Digitas, Starcom MediaVest Group, and Zenith Optimedia Group, closed Tuesday at $34.95, near their low of $34.15, and off their high of $49.40.

Shares of Aegis Group closed Tuesday at $2.10, near their recent low and a number of Aegis insiders have recently begun exercising options and buying shares.

The downgrades appear to reflect recent economic uncertainties, as well as the lingering effects of the TV writer's strike on U.S. ad spending amid mounting concerns of a new economic recession. Already, some analysts believe that the U.S. ad economy is in a recession, or a period of "stagflation" with little of no expansion in advertising budgets, but others argue the industry's tracking data does not accurately reflect the growth of below-the-line marketing services and newer forms of media, especially online and emerging media.

Shares of Google's stock, meanwhile, continue to serve as the poster child for the new media economy. Shares of Google closed Tuesday at $648.54, near their recent high, as a Credit Suisse equity research report issued a 12-month target price of $900 a share.