The workers contracted tumours linked to asbestos exposure while working at the company’s factories during the 1970s and 80s, Ansa reported.
A Milan court handed the ex-managers of Pirelli, which was taken over by ChemChina in March, jail terms of up to seven years and eight months.
Relatives of the victims cheered when the conviction was announced in court, and displayed banners saying: “We showed that when you are united, you can win”.
The ruling follows a controversial decision by the Court of Cassation last November to overturn the conviction and 18-year prison sentence given to tycoon Stephan Schmidheiny over inadequate safety provisions in asbestos-cement plants run by his now defunct group Eternit in Italy in the 1970s and 80s.
The conviction related to nearly 3,000 abestos deaths.
Italy's top court ruled that Schmidheiny, a scion of a Swiss industrial dynasty now regarded as a philanthrophist, should not have been convicted of causing a health or environmental catastrophe because the verdict came more than 12 years after the crime and was therefore subject to the statute of limitation applicable to the specific charges.
Italian Prime Minister Matteo Renzi vowed at the time to change the country's “nightmare” statute of limitation rules after the conviction was quashed.
The pursuit of Schmidheiny was the biggest case of its kind against a multinational over asbestos-related deaths.