Greenberg has been with the company for 21 years. He is set to leave at the end of the month and will be replaced by Jim Cantalupo, the former president and vice-chairman of the company, who is returning to the company after a short period away.
The McDonald's brand has suffered several setbacks in recent years with the publication of books such as 'No Logo' and 'Fast Food Nation', which have given large US brands such as McDonald's bad publicity.
The battle with fast food rivals such as Burger King and KFC has also seen McDonald's profits fall. The company is also said to be worried about the lawsuits threatened by overweight customers.
Although the company has publicly dismissed the legal challenges as absurd, it is said to be quietly concerned that if one case sticks, it could be faced with damages of similar scale faced by the tobacco industry.
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