PizzaExpress and Ask pizza and pasta restaurants are to float on the London Stock Exchange before Christmas.
Owners TDR Capital and Capricorn Ventures International will float the combined pizza businesses through operating company Gondola Holdings.
TDR and Capricorn hold an 80% stake in the businesses and will remain majority shareholders after the flotation of the new holding company, which is expected to value the business at about £800m.
The flotation will involve all the Ask brands, including Zizzi, Jo Schmo's, Lupo and Bar and Grill as well as all PizzaExpress branded outlets. It will not include the TDR-owned PizzaExpress brands of Caf Pasta, Marzano, Riviera, Kettners and Gourmet Pizza.
TDR and Capricorn acquired the underperforming PizzaExpress group in June 2003, then bought Ask Central in May 2004 to become the leading player in the premium eat-in pizza and pasta market.
The revitalised group now operates 497 restaurants in the UK and Ireland, serving 30 million meals a year and employing 10,741 staff.
In the year to 26 June it boosted overall earnings before interest, tax, depreciation and amortisation by 12% to £84.6m on turnover of £371.3m.
The owners also outlined a new board structure for Gondola, to be chaired by David Ross, current deputy chairman of the Carphone Warehouse.
Harvey Smyth and Jo Fleet will continue as chief executives of the Ask and PizzaExpress businesses, respectively.
Karen Jones, chief executive of pub operator Spirit, has been named as one of three new non-executive directors.
By Angela Frewin