A statement issued by Endemol said that Agut Bonsfills had resigned for "personal reasons" and the board accepted the resignation last night.
"The supervisory board has taken steps to arrange for Mr Agut's succession without delay. The company expects to make a further announcement shortly," the statement said.
Agut, a Spaniard, was handed the chief executive job by Endemol's parent company Telefonica two-and-a-half years ago.
Recent reports have indicated that the telecoms company is preparing to sell Endemol, also behind Channel 4's 'Deal or No Deal', which it bought for €5.5bn in 2000.
It currently owns 75% of Endemol, having floated 22.3% of the company on the Dutch stock market last November.
Endemol's other top managers are chief creative officer Peter Bazalgette and chief operating officer Tom Barnicoat.
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