Omnicom Shares Erase Gains as Traders Show Doubt Related to Deal with Publicis

Shares of Omnicom Group (NYSE: OMC) have sold off very sharply over Monday's trading session, moving from as high as $70.50 (up more than 7.4 percent) to now under $65 (down about 0.7 percent from Friday's close). While traders initially cheered the deal between Omnicom and Publicis, a bit of skepticism from several sources has traders taking profits heading into the close.

• The Group CEO of WPP plc (NASDAQ: WPPGY), Martin Sorrell, earlier said the deal between Omincom and Publicis did not "add up.";
• Goldman Sachs' Drew Borst warned the corporate cultures of Omnicom and Publicis could clash; and,
• Macquarie's Tim Nollen pointed at likely regulatory and/or client conflictions.