The "micro-convenience" stores will sell up to 150 products including chilled foods, newspapers, snacks and confectionery in one section of the store with alcohol in another.
Trading director Lloyd Stephens said this did not mean the chain was moving away from its roots as a specialist off-licence, but offering more choice was key to the company's survival.
He said: "It's incredibly tough to serve as a stand-alone off-licence. What we have found is that by adding other categories we can add footfall, revenue and profit to our stores.
"Our vision is to be the UK's largest successful specialist retailer through Threshers and Local licensed convenience stores."
A two-year trial has already seen 24 Local branches become what Thresher calls "full" convenience stores, dedicating 40 per cent of space to convenience goods. Another 37 were converted to micro-convenience stores where 10 per cent of the space is used to display key distress-purchase products.
Stephens said stores that had become full convenience on average had seen alcohol sales rise 5 per cent and customer numbers had gone up by 40 per cent. Drinks sales have risen by up to 10 per cent at micro-convenience stores.
The group plans to introduce the format to the Threshers fascia following the initial roll-out across its Local stores.
Thirty Local stores in England and 30 in Scotland are also continuing to trade under the Discount Booze banner as part of a three-month trial.
The stores offer bigger discounts on alcohol, with case deals featuring as well as the group's three-for-two discount. They also sell grocery products.
Stephens said the stores were designed to trade on lower margins but encourage more customers through the door.