Food giant Heinz is to sell its frozen and chilled food business, which employs 2,300 workers in the UK and Ireland.
The company last night said it will look for potential buyers over the next six to 12 months for the business as part of a "transformation plan".
The move is part of the sale of Heinz's European seafood and frozen and chilled food businesses, which the company said would enhance sales and earnings growth.
Heinz Europe president Joe Jimenez said the plan would make the company more "leaner and nimble" and allow it to invest in its three core products, including ketchup and meals.
Paul Kenny, acting general secretary of the GMB union, said: "GMB members working for Heinz have enjoyed good industrial relations with a wealth of family-friendly policies. GMB will expect any new owner to continue with the good practice that is in place now so that our members can continue to work for the benefit of the company and themselves. The local communities rely on the work provided by their local Heinz sites and could easily be devastated by any changes to them."
The announcement comes less than a week after Unilever said it was considering its options for Birds Eye and its other European frozen food operations.
Unilever is likely to consider an outright or partial sale among a range of possible moves for the frozen food division, which trades in 11 European countries but has recently disappointed in terms of sales.
The study covers Birds Eye in the UK, where the company operates manufacturing facilities at Hull and Lowestoft, as well as the Findus and Iglo brands outside of the UK.