Blackstone and PAI, which was already a shareholder in United Biscuits, acquired the company's UK and northern European business for a reported £1.6bn this week.
An industry insider said he had expected that United Biscuits "would have sold for more". The private equity firms were likely to work with each other to achieve a higher exit price, he added, "either through a sale to Kraft Foods or a stock market flotation within the next year to 18 months". In September, Kraft Foods acquired United Biscuit's Spanish and Portuguese operations.
United Biscuits also announced it was transferring production of Nik Naks and Wheat Crunchies, which it acquired in February, to Ashby-de-la-Zouch and Teesside next year.