The company which owns St George's shopping centre in Preston has been put into administration.
Alex Williams and Andrew Dolliver of Ernst & Young (EY) LLP have been appointed as administrators for IRAF UK Dragon Ltd Partnership.
EY said the shopping centre would "continue to trade" during the administration process.
Council leader Matthew Brown tweeted his "real concern" and said the council would "closely monitor" the situation.
In a statement, he added it was "disappointing" and the council hoped a "beneficial solution" could be found.
He said the pandemic had "caused great disruption" to retail and it was "difficult news on the back of recent announcements about Debenhams and other big names leaving the high street".
Management firm Sovereign Centros will run the centre as essential shops remain open during Covid-19 lockdown.
Mr Williams said: "The administration of the partnership and the companies will have no operational impact on St George's Shopping Centre which continues to trade in compliance with government Covid regulations on a business as usual basis."
Situated on Friargate, St George's houses shops including Marks and Spencer, Superdrug, New Look and River Island.
The centre was first opened in March 1966, originally as an open-air centre and has since had several revamps.
Mr Brown said "a fresh look" at how high streets were utilised was "vital", with a greater focus on community and social uses for units.
A spokesman from Preston Business Improvement District (BID) said the pandemic had had an "incredibly adverse effect on bricks and mortar retailers" but it was confident St George's would remain as "an integral part" of the city's retail offer.
He urged residents to continue to support St George's and help local businesses "bounce back" from the crisis when shops were allowed to reopen.