Time Warner-Fox merger would be great for advertisers: Martin Sorrell

Though Time Warner CEO Jeff Bewkes rejected Rupert Murdoch's offer for the company, another CEO is hoping the deal will happen.

The CEO of the world's largest ad conglomerate, WPP's Sir Martin Sorrell, told CNBC a deal would be "really interesting," as a merged company would give advertisers much easier access to a more diverse assortment of ad inventory.

Sir Martin Sorrell
Dario Pignatelli | Bloomberg | Getty Images
Sir Martin Sorrell

"If they were able to form joint sales organizations, it would be good for our clients," Sorrell said in a telephone interview Wednesday. "From a content point of view it would be very interesting, from a digital point of view it would be very interesting—look at the multiplicity of platforms, the opportunities for legacy businesses to leverage digital assets. And from a global point of view it looks very interesting because Fox and News Corp's assets have always been more global than other media assets, and Time Warner would be able to instantly leverage assets outside of the US globally."

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But would a massive media giant with unprecedented advertising scale put WPP and the other ad giants at a disadvantage when it comes to negotiating rates? Sorrell says no, that he wouldn't worry about being disadvantaged in negotiations unless there were just one or two media giants. With enough buyers, a new megaconglomerate would instead give better tools for better ad buying.

By CNBC's Julia Boorstin