USA-based food group General Mills is to close its Jus-Rol pastry factory in Berwick-upon-Tweed, Northumberland.
The factory currently employs around 256 people and produces baking mixes and frozen doughs.
However, the site could now close as soon as autumn 2016 as General Mills looks to streamline its business. The company said the plans were subject to consultation with union officials.
Rab Donnelly, area organiser for the Union of Shop, Distributive and Allied Workers (USDAW), said: “We will be meeting with the on-site reps and management as soon as possible to look at the business case for the closure and what can be done to keep the site open. The site is one of the town’s biggest, if not the biggest, employer with more than 50 years history in Berwick.
“This is a very upsetting day for the people of Berwick and our members will be rightly very worried about their future.”
A General Mills spokesman said the proposals were being made after a review of its European and Australasian manufacturing and distribution network.
The spokesman said: “The review revealed we needed to address excess capacity in our UK baking business by consolidating manufacturing production within the supply chain network.
“This proposal is in no way a reflection of our employees in Berwick, who have worked hard to support the business.”