Cadbury Schweppes has put the division behind Butterkist popcorn up for sale as part of its policy of selling off non-core brands.
Butterkist has a 44% share of the UK popcorn market
The Monkhill business also makes own-brand sweets for supermarkets and has plants in Pontefract, York, Leeds and Cleckheaton in West Yorkshire.
Cadbury expects the sale to be complete by the end of the year, with about 800 staff transferring to the new owners.
Monkhill generates sales of £80m each year, according to Cadbury.
Small brand sell-off
The company recently overtook rival Mars as the world's biggest selling confectioner, with a market share of about 10%.
Cadbury's brands include 7Up, Dr Pepper, Trident, Bassett's, Trebor, Halls and Green & Black, and it earns about 80% of its sales and profits outside of the UK.
Finding a buyer for Monkhill is part of its plan to sell-off some of its smaller brands.
Earlier this week, Cadbury agreed to sell its South African drinks business, having already sold its European drinks division back in February.
In the same month it reported a 13% rise in underlying pre-tax profits for 2005, at £837m ($1.5bn).