Amat, the public transport company in Palermo, allowed the member of staff to take the same 15-days marital leave entitlement granted to heterosexual couples, Il Giornale reported.
The company initially declined the request from Giuseppe Anastasio, 47, in June last year, on the basis that the couple could not provide a marriage certificate.
His civil union to 53-year-old Salvatore Migliore was registered in Palermo, which like several other major Italian cities has a civil union registry, although most are symbolic and not legally-binding.
Following the intervention of National Office against Racial Discrimination (Unar), the request was reviewed by the company's new director, who gave the holiday the go-ahead.
“What Amat has done has set a very important precedent,” Flavio Romani, the president of Arcigay, Italy's biggest gay rights organization, was quoted on Fanpage.it as saying.
Amat has followed in the footsteps of a number of private companies, including Telecom Italia and Intesa San Paolo, in giving marital leave to gay staff.