The American burger chain Wendy’s is to open a string of “dark kitchens” in the UK to serve growing demand from the home delivery market.

The company, which is returning to the UK more than 20 years after beating a retreat, said it would open up to 10 of the delivery-only kitchens by the end of this year, some of which could be run from trucks.

Abigail Pringle, the president of Wendy’s international business, said the dark kitchen sites, run via a franchise with specialist operator Reef, would form part of a plan to eventually have up to 400 outlets in the UK.

Wendy’s opened its first new UK restaurant in Reading in June and plans to have five more restaurants by the end of the year. Outlets are due to open in Stratford in east London as well as Oxford and Croydon. The company is also talking to 30 potential restaurant franchise partners to help with expansion.

Pringle said the first store was trading well, with customers tending to order the products Wendy’s was best known for, including the Frosty, a frozen dessert first launched in 1969.

She said the dark kitchens, which would initially all be in London, would form a “meaningful contribution” to the company’s UK growth plans as part of a “accessing consumers through multiple channels”.

“The UK’s delivery [market] has continued to grow year after year. Humans like convenience and that’s always going to be a part of what they are looking for.”

She said food from the dark kitchens, the first of which will open “within weeks”, would be delivered via Reef’s partnerships with major specialists, which include Uber Eats and Deliveroo.

Wendy’s UK use of the delivery-only kitchens comes after it tested the concept in the US and Canada. In Canada it also partners with Reef, which runs the kitchens from what it calls “vessels”, which can be trucks, shipping containers or repurposed warehouses or shops.

In the UK, Pringle said Wendy’s would consider a variety of locations, potentially including trucks, railway arches and industrial estate units.

Pringle said Wendy’s return to the UK would be more successful than its previous attempt in the 1980s because the company was “fully committed to long-term growth in the UK” including significant investment in company-owned restaurants.

Wendy’s is one of the first major brands to try out dark kitchens at scale in the UK, where they have proved controversial because of concerns about working conditions.

However, McDonald’s trialled a site in Hounslow in 2019 and Wagamama has about five sites with plans to open more.