Sainsbury’s has launched a concession tie-up with Fat Face as it ramps up efforts to bring third-party retailers and services into its larger stores.

Retail Week can reveal the grocer is piloting the partnership at stores in Sydenham, south London, and Calcot, Reading.

Sainsbury’s said the addition of Fat Face ranges would “complement” its existing Tu clothing lines.

The Fat Face shop-in-shops will be open in time for the crucial Black Friday and Christmas trading periods.

Sainsbury’s said more could be rolled out next year “if the partnership proves successful”.

The trial comes as Sainsbury’s accelerates efforts to build partnerships with other businesses to broaden its proposition in its largest supermarkets.

It has already joined forces with the likes of Oasis and Clarks, which have taken space in Sainsbury’s supermarkets.

The grocer has now given more than 400,000 sq ft of store space to third-party concession partners.

Sainsbury’s head of clothing Rebecca Hitchings said: “Growing our clothing business is a key part of our strategy to make shopping more convenient for customers. We are rapidly becoming a leading fashion destination and are now recognised to be a top UK clothing retailer.

“Fat Face will complement our existing ranges and we’re delighted to be welcoming such a well-loved retailer with a passion for sustainability to our stores in time for Christmas.”

A Fat Face spokeswoman added: “We are delighted to be partnering with Sainsbury’s on this trial. Fat Face and Sainsbury’s have a natural alignment on customer demographics and this partnership will allow customers to shop Fat Face product in a way that is most convenient to them.”

Sainsbury’s supermarket rivals are increasingly pursuing similar strategies as they seek to make better use of excess space in out-of-town big-box stores that have become out of kilter with modern shopping habits.

Tesco has partnered with the likes of Next, Arcadia and Dixons Carphone, Asda works with Decathlon and McDonalds, while Morrisons has brought Timpson shop-in-shops and Amazon lockers into several stores.