The Casual Dining Group, which owns Bella Italia, Las Iguanas and Café Rouge, has entered administration, with dozens of restaurants across the UK at risk.
More than 1,900 jobs are set to be axed, though 4,000 are reportedly secure for now.
Around 91 of 250 outlets will close, with administrators now reassessing the firm’s finances.
Casual Dining Group said that given the “extreme operating environment” it was in the best interests of all stakeholders to enter administration to allow the company to conclude negotiations with landlords over its estate.
Most of the closures affect the Café Rouge and Bella Italia brand, although 11 Las Iguanas outlets, three Belgo restaurants and several sites at airports will also shut.
Chief executive James Spragg said: “After reviewing all our options with advisors, it became clear that we needed to take this action in order to protect the business and secure the best possible future for Casual Dining Group as we look to conclude a potential sale.”
Joint administrator Clare Kennedy of Alix Partners said: “Our immediate priorities are to assist those whose employment has been affected by today’s announcement and to secure a sale for the group in order to protect jobs and provide the group’s much-loved brands with a sustainable platform for the future.”
The announcement comes as Frankie & Benny’s bosses announced plans to close 125 stores immediately – with no plans to reopen the branches on Saturday, July 4.
A total of 61 Chiquito sites will also permanently close, while EAT has been axed from the UK entirely.
Dining chain Carluccio’s is also preparing to axe branches despite been bought in a rescue deal which will save 30 of its restaurants last month.
Burger chain Byron, which employs around 1,200 staff, filed a notice to appoint administrators from KPMG on Monday.
It is understood that the move will be used to provide protection from creditors as it holds detailed talks over a potential rescue sale.
The burger chain, which runs 51 sites, started a sale process with KPMG earlier this year after being forced to shut its sites in the face of the pandemic.