The maker of Hula Hoops and McCoy's has been sold to the German snacks group behind Pom-Bear in a deal worth $640m (£400m).
United Biscuits, which is owned by the private equity groups Blackstone and PAI Partners, sold KP Snacks, which also makes Space Raiders, Nik Naks, Skips, Discos, and Frisps, to Intersnack.
United said it will retain ownership of baked bagged snacks manufactured in its biscuit factories, including Mini Cheddars and Twiglets.
KP Snacks has an annual turnover of £280m and employs 1,500. The combined business will have revenues of more than £1.7bn and 8,000 staff.
David Fish, the United Biscuits chairman, said: "This exciting deal ensures that the KP brands continue as part of a major European snacks business … and allows UB to concentrate its attention solely on continuing to develop and grow its baked biscuit and snack product range."
The UK is the biggest snacks market in Europe, United Biscuits said.
It hired bankers from Credit Suisse and lawyers from Freshfields for advice, while Intersnack bought in Goldman Sachs, Ernst & Young and McDermott, Will & Emery.
Blackstone and PAI bought United Biscuits for about £1.6bn in 2006.