The news comes as WPP, headed by CEO Sir Martin Sorrell, further extends the deadline for acceptances by another week. Shareholders now have until October 29 to accept the offer, although the Takeover Panel, which will rule on whether or not WPP must proceed with the bid, may hand down its decision before then.
WPP has not revealed what new information it has found to back up its argument that the Takeover Panel should invoke the material adverse change condition, which would allow WPP to get out of its bid for Tempus.
It beat off a challenge from Havas Advertising to buy Tempus, but since the events of September 11 in the US, along with the overall downturn in ad revenues, WPP looks to be paying too much for Tempus.
The media-buying company is fighting back, arguing to the Takeover Panel that WPP must pay the full £434m for the company. Tempus shareholders have threatened legal action if the material adverse change clause is invoked.
WPP's third-quarter results are due this week. Its shares rose 8.5% in yesterday's trading to close at 537.5p and look set to continue their upward trajectory, rising by 1.6% in early morning trading.