Food giant Nestle is to axe 645 jobs in York as part of a major restructuring plan, it has announced.
Nestle axed 234 jobs in York earlier this year
The Swiss firm said part of its site in the city would be sold and some products moved to other factories in the UK and in Europe.
Union officials have described the cuts as a "devastating blow" and have pledged to fight redundancies.
The announcement follows an earlier cut of 234 Nestle jobs and takes York's job losses to more than 1,600 in a year.
Last week Aviva, which owns Norwich Union, announced 450 job cuts in the city. In the past year, York has also suffered job cuts by Terry's and British Sugar.
'Fit for future'
Under the terms of the company's plans Black Magic will be made in the Czech Republic, Smarties in Germany and Dairy Box in Spain.
Nestle said it hoped at least half of the job losses, which will start next year, could be achieved through voluntary redundancy or early retirement.
The firm said it would continue to employ more than 1,800 people in York.
Chief Executive of Nestle UK, Alastair Sykes, said: "The UK confectionery market is very competitive.
"Our Nestle Rowntree business has market-leading brands and strong potential, and this restructure and investment programme will ensure that it is competitive and fit for the future."
But GMB union organiser John Kirk said the firm had failed to invest in its York site.
He said: "Nestle's reasons for exporting so many jobs - namely that the plant and buildings are old and out of date - are self-serving.
"Nestle took the profits from the brands year in and year out and Nestle themselves failed to invest adequately in the plant and building in York.
"To use this neglect as the reason to move heritage brands to plants overseas where Nestle did invest is not acceptable. The move will be fiercely resisted."
The GMB also claimed Nestle had given notice that it planned to terminate the current pay and conditions of employment for 1,500 workers at its York factory.
"All in all, this is a bleak day for York", Mr Kirk said.
City of York Council said it was "saddened" by the announcement.
Bill Woolley, director of city strategy for the authority, said: "It is, however, significant that the company has signalled its ongoing commitment to York with proposals to invest £20m in its production facility.
"They have assured us that their plans will help to safeguard the remaining jobs for the future. This is extremely important for York's future economy."
Mr Woolley said the council's first priority was to support those made redundant.
He added: "Despite recent announcements, York's economy remains buoyant and we will continue to work with partners across the city to attract new jobs to the area through initiatives such as Science City York."