The patron was 68 years old and was at the helm of the Bergamo club for 14 years, passing on the baton to his 21-year-old son Alessandro when he fell ill.
Ruggeri had been undergoing tests in hospital on January 16 2008 when he was struck by a brain haemorrhage.
He never woke up from emergency surgery and had been in a vegetative state ever since.
The Ruggeri family sold Atalanta to Antonio Percassi in June 2010.
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