WPP will raise the cash in convertible bonds. The bonds will be convertible into WPP stock in 2007, with interest payments of 2% annually. It said the funds raised by the issue will be used to pay for Tempus and for "general corporate purposes".
It has given an additional £50m in bonds to the banks managing the deal, Merrill Lynch and Schroder Salomon Smith Barney, to sell in the next few days.
WPP's Sir Martin Sorrell drew heavy flack after launching his hostile counter-bid for Tempus against an agreed £425m from French group Havas Advertising. Sir Martin looked set to try to pull out of the deal, but in the end bowed to City regulators and went through with the purchase.
The deal led to the Tempus-owned CIA being merged with WPP's The Mediaedge to create Mediaedge:CIA, the world's fourth-largest media planning and buying network.
WPP is the second-biggest advertising group in the world. Last year, it was named as the UK's most acquisitive company, spending £352.8m buying other companies in 2001, a figure that does not include Tempus.
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