The Week: City News - Sorrell accuses rival GfK

Sir Martin Sorrell, the WPP Group chief executive, has said GfK, his rival to take control of TNS, should "put up or shut up" and has accused it of misleading the stockmarket.

Speaking to Reuters in China, Sorrell said: "They are misleading the market. They say they have access to an unidentified but substantial source of capital. It is time to put up or shut up." Sorrell said WPP could consider other market research acquisitions, including Nielsen, IMS Health and Synovate, if it fails to secure the TNS deal.