The decision was made during talks with union leaders from the Umbria branch of Fai-Cisl on Thursday, the company said in a statement.
Marilena Petruccioli, who works at the company's Perugina plant in Perugia, will instead be subjected to a disciplinary measure, rather than be dismissed, after a compromise was reached with the union.
Nestlé Italy said that the company and union fully agreed that food safety and hygiene standards are "non-negotiable" values of the company, with both sides recognizing the "inappropriateness of Petruccioli’s social media comments, because they could send out a misleading message about the importance of food safety".
The offence took place on October 30th, when Marilena Petruccioli posted a message on her Facebook page expressing her disgust after reading a disciplinary note from “the head of personnel” at "this company" in which the person purportedly compared a member of staff to a dog.
Petruccioli said in the post that the manager should be "put under review" for using the word 'collare', meaning 'dog collar', in reference to a foreman who had been disciplined for flouting health and safety rules at the company's factory in Perugia, La Repubblica reported.
"'Il collare' is worn by dogs, not people," she wrote. "Certain people who hold certain roles should be careful about the terms they use in certain official actions."
Although Pertuccioli, who is also a union representative for staff at the factory, didn’t name the company, she was dismissed earlier this month for "publicly attacking the company’s personnel managers".
Nestlé Italy said in a statement on Wednesday that Pertuccioli had "ridiculed" company managers on social media for their efforts in "enforcing stringent sanitation and security measures” in order to “protect workers, products and customers."
The company added that the disciplinary action referred to in the message was taken against a factory foreman for not wearing appropriate overalls while working on a production line.
It said the public comments had “undermined the authority” of those in charge of enforcing health and safety regulations.
“From a trade union representative, who has the responsibility of representing hundreds of people working in the largest plant of the Nesté group in Italy, we expected support and not criticism of efforts to ensure safety in the workplace.”
Pertuccioli has been working for the company since 1996 and was placed under Italy’s “protected” workers category after becoming disabled following a workplace accident in 1997.
Dario Bruschi, the president of Fai-Cisl Umbria, claimed the Facebook post referred to something that "happened in another company" and "that a series of circumstances might have led to the belief that it referred to Nestlé-Perugina".
But Nestlé Italy dismissed the claim, saying it "was misleading to attempt to represent and minimize the repeated comments of Mrs Petruccioli as being unrelated, or related to the context where she works."