The proposed sale by Premier Foods, which also owns Hovis, Mr Kipling and Bisto, includes other Branston products such as ketchup, relish, salad cream and mayonnaise.

The business is being bought by Japan's Mizkan, which recently acquired Premier's vinegar brand, Sarson's, and pickles business, Haywards. It already has operations at Burntwood in Staffordshire and is a major supplier of rice vinegar in the UK.

Branston, which is named after the village near Burton in Staffordshire where Crosse & Blackwell first produced it in 1922, sells an estimated 28 million jars a year of the pickled relish, which is made to a secret recipe.

Premier acquired the Branston business as part of its acquisition of certain Crosse & Blackwell operations from Nestle in 2002.

Around 350 people who work at Premier's Bury St Edmunds factory in Suffolk will transfer to Mizkan as part of the proposed deal, which is due to complete early next year.

The disposal means debt-laden Premier will have raised £370 million from the sale of a number of non-core brands, including Robertson's marmalade and Gale's honey. It is also well ahead of its target of £330 million by June 2014.