Billionaire Michele Ferrero, who became Italy's richest man with a confectionary empire built on his popular Nutella spread, has died aged 89.

Ferrero had been battling illness for several months and died in Monte Carlo yesterday.

He's being described as a true entrepreneur, known and loved in Italy and abroad.

It was Ferrero's father, Pietro, a small-time pastry maker, who laid the groundwork for the Nutella recipe, famously adding hazelnut to the mix to save money on cocoa, which was in short supply after World War II.

But Michele Ferrero turned the paste into the Nutella now known the world over, with about 365,000 tonnes made every year.

Its products earned about almost US$12 billion in the year to August 2014.