The Restaurant Group has said it plans to close over 150 sites as part of a restructure following its takeover of Wagamama.
Last year the Restaurant Group, which also operates Frankie & Benny's, Chiquito, Garfunkel's and Coast to Coast, purchased Wagamama for £559m.
Having reported a £87.7m pre-tax loss for the first half of this year, it said that some 88 Chiquito and Frankie & Benny's sites would close in the next six years with 100 more in the longer term, or as soon as its leases would allow.
The move would halve the Restaurant Group's portfolio of 352 sites, though it said that 15 would be converted into Wagamama restaurants.
Like-for-like sales for the 26 weeks to 30 June 2019 were up 4%, with total sales rising 58.2% to £515.9m.
The operator of Frankie and Benny's, Garfunkel's and Chiquito, said that the plans for Wagamama, which the group bought last year for £559m, were "on track and progressing well".
Debbie Hewitt, non-executive chairman of TRG, said: "We are mindful of the headwinds in the casual dining sector and the meaningful uncertainties created by the potential of a ‘no-deal Brexit' and are planning with this in mind. However, our business is now better diversified and purposefully positioned to benefit from multiple opportunities for growth."
The end of the first year of trading, TRG's UK portfolio was made up of 356 leisure sites (240 Frankie & Benny's, 80 Chiquito, 13 Coast-to-Coast, eight Garfunkel's, six Filling Station, five Firejacks and four Joe's Kitchen), 135 Wagamama sites, 70 concessions and 82 pub restaurants.