The Co-operative Group is to roll out its ongoing store formats trial to further stores following “encouraging” results.

The society has been trialling new formats and ranges suited to local demographics for the past six months in a bid to reverse falling sales.

Releasing its full-year results this week, CEO Peter Marks said the new formats were being trialled in 60 stores. “It’s early days but there have been some very encouraging results,” he said.

The Co-op has previously reported double-digit sales growth in the trial stores as well as strong fresh sales. Marks said the trial would roll out this year, and own-label NPD and customer service would also be prioritised.

The Co-op reported a 0.7% fall in like-for-like sales for the 53 weeks to 5 January. Although like-for-likes were down in the first three quarters of the year, they rose by 0.3% in the final quarter. Full-year like-for-likes also rose 1.9% in its core convenience estate.

Underlying operating profits fell 9.5% to £288m on sales up 1.4% to £7.44bn as the society absorbed “significant” inflation and cut operating and overhead costs to invest in service, price and promotions.