Sorrell tells GfK its 'time to put up or shut up' over TNS

LONDON - WPP Group chief executive Sir Martin Sorrell has accused GfK, his rival in the battle to take control of TNS, of misleading the stockmarket over its intention to buy the market research group.

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 added that there were other market research acquisitions WPP could carry out if it failed to land TNS, including Nielsen, IMS Health, and Synovate, owned by Aegis.

Two weeks ago WPP posted a £1.08bn offer to TNS shareholders, which was rejected by the TNS board. Shareholders are due to vote on the offer on August 29.

Meanwhile, Nuremberg, Germany-based GfK has been working on delivering a bid for TNS that will be competitive with WPP's 260.6p per share offer.

Since confirming on July 9 that it was seeking to acquire TNS rather than merge with it, GfK has not made an offer and has admitted there is no certainty that it will.

Reports claim that GfK has held talks with private equity companies Cinven and Apax Partners and with Gunter Herz, a wealthy German who made part of his fortune from the Tchibo cafe chain.

According to the Daily Telegraph, GfK needs between £400m and £600m from its partner to rival WPP's offer.

TNS's share price opened unchanged this morning at 273.75p.