Zizzi and Ask Italian are set to permanently close 75 of their restaurants, putting up to 1,200 jobs at risk.
Azzurri Group, the owner of the two chains, has been pulled from administration by US investment firm TowerBrook Capital Partners after the coronavirus crisis rocked the industry.
As part of the deal, 225 restaurants and shops have been saved along with 5,000 jobs – but 75 will not reopen.
Steven Holmes, the chief executive of Azzurri Group, said the “profound impact” of the UK lockdown on the casual dining sector had brought the company “to a standstill”.
He added: “Despite being a successful operator, the immediate loss of revenue during lockdown meant that we have had to make some incredibly difficult decisions to protect the business for the long-term.
“It is with deep sadness that this process will result in the permanent closure of a number of sites and that we must say goodbye to greatly valued employees across our brands.”
The cuts on Friday mark the latest casualty for British business as COVID-19 restrictions begin to ease.
More than 88,000 jobs have been lost due to coronavirus, with at least 12,000 of those in the hospitality sector.
Among the hospitality brands making cuts are the Casual Dining Group, which owns Bella Italia, Cafe Rouge and Las Iguanas; Carluccio’s, Pret a Manger and Le Pain Quotidien.
Pizza Express is also expected to announce the closure of around 75 restaurants.