Deltic Group has filed notice of intention to appoint administrators, although hopes remain that the group could be rescued by an acquisition.
Deltic is one of many late night businesses hit hard by coronavirus restrictions in the UK. It has been unable to operate any of its venues as nightclubs since March.
Names that have been reported as interested bidders include Scandinavia's largest nightlife group Rekom, and private equity firms Greybull Capitaland Aurelius.
Until this year, Deltic Group ran 53 clubs and late-night bars across the UK, with brands including Atik, Prysm and Oceana. The business put itself up for sale in October in a bid to stave off bankruptcy.
A cross-party group of MPs and peers have joined forces to give a stronger voice to late-night businesses in parliament. The All-Party Parliamentary Group for the Night Time Economy will work with the Night Time Industries Association, which has warned that nightclubs face "extinction from UK culture" without further intervention. It has called on the government to compensate businesses that are unable to trade.
Revolution Bars closed six sites and moved to a turnover-based rent on seven others after entering a company voluntary arrangement last month.