Pizza Express is considering closing 15% of its UK restaurants, which would mean the loss of 1,100 jobs.
The chain is the latest High Street outlet to undertake a restructuring of its business after trading was halted by the coronavirus pandemic.
It is poised to launch a Company Voluntary Arrangement deal in the near future, which could mean 67 of its 449 outlets will close.
But it said the final outcome of the restructuring has "yet to be decided".
The company closed all its UK restaurants on 23 March after the Government-mandated lockdown.
Pizza Express has heavy debts and last year was known to have started talks to put its debts of more than £1bn on more favourable terms.
Andy Pellington, group chief finance officer, said in a statement: "While we have had to make some very difficult decisions, none of which has been taken lightly, we are confident in the actions being taken to reduce the level of debt, create a more focused business and improve the operational performance, all of which puts us in a much stronger position."