Fashion chains Peacocks and Jaeger have fallen into administration, putting more than 4,700 jobs and almost 500 shops at risk.
It comes after owner Edinburgh Woollen Mill Group failed to find a buyer for both businesses.
No redundancies have been announced yet and no stores closed.
Tony Wright, joint administrator of the business from FRP Advisory, said talks with potential buyers were still going on.
“Jaeger and Peacocks are attractive brands that have suffered the well-known challenges that many retailers face at present,” he said.
“We are in advanced discussions with a number of parties and working hard to secure a future for both businesses.”
In a statement, Edinburgh Woollen Mill Group said: “In recent weeks we have had constructive discussions with a number of potential buyers for Peacocks and Jaeger.
“But the continuing deterioration of the retail sector due to the impact of the pandemic and second lockdown have made this process longer and more complex than we would have hoped.”
It said that a “standstill agreement” secured with the High Court that temporarily put off administration had now expired.
“Therefore as directors we taken the desperately difficult decision to place Peacocks and Jaeger into administration while those talks continue,” it said.
It comes two weeks after Edinburgh Woollen Mill called in administrators for its eponymous clothing chain and its homeware brand Ponden Home, putting thousands of jobs at risk.
Jaeger is a London-based fashion business with 76 stores and concessions and employs 347 staff. Cardiff-based Peacocks operates 423 stores with 4,369 staff.