Like the rest of Europe, Italians in recent years have embraced the U.S. tradition of Black Friday, a day of heavy discounting by retailers on the day after Thanksgiving.Unions said in a statement more than 500 Amazon workers at the Piacenza site in northern Italy had agreed to strike following a failure to negotiate bonuses with the company.

Workers have also decided not to do any overtime until Dec. 31, covering the peak season for the online retailer which hires temporary workers during this period.Amazon employs around 1,600 people on a permanent basis at the Piacenza site, the first it built in the country after launching its Italian website in 2010.Amazon said in a statement it remained focused on trying to guarantee scheduled deliveries for its customers on Black Friday and in the following days.The company said salaries paid to its workers were among the highest in the logistic sector and that it also provided some benefits such as private medical insurance or money to pay for training programmes.E-commerce is growing fast in Italy where online sales account only for 10 percent of overall retail sales, according to consultancy EY, half the European average.