Private equity group Gordon Brothers Europe said 32 jobs will be cut at the chain’s Uxbridge headquarters, while 264 stores are at risk as a buyer is sought.
The chain plunged into administration in January, before being bought by Gordon Brothers in March. At the time of its initial collapse the group had 528 stores in the UK employing 4,190 staff.
Gordon Brothers said its turnaround attempts for the historically loss-making company coincided with a patch of poor trading across rental and retail sales.
It said stores will continue trading but some may need to close if a buyer cannot be found.
Blockbuster has been hit hard by intense competition from supermarkets, as well as the shift from physical rental and sales to online games, music and films.
Gordon Brothers said it tried to turn around the chain by restructuring, investing in marketing and negotiating new deals with landlords.
But it failed to broker a licensing deal with US company Blockbuster LCC, which owns the brand, for a new digital platform.
It said efforts will now focus on “giving the company a chance of future survival through a reduced and different business model in the hope that a buyer will be found”.
Gordon Brothers describes itself as one of the “largest buyers and sellers of under-performing consumer products worldwide”.
It has also helped finance Bradford-based shoe chain Barratts.