The Co-op Group has announced a 10% increase in sales for the first half of 2018 to £5bn, driven by a strong food sales performance and the completion of its acquisition of Nisa.

Like-for-like food sales were up 4.4% compared to last year, with core convenience like-for-like sales up by 5.1%, marking the 18th consecutive quarter of like-for-like sales growth.

Group profits before tax also increased to £26m during the same period, from £14m in 2017, helped by a strong performance for stores during the World Cup.

The Co-op now supplies food to more than 7,700 stores, including Costcutter and Nisa retailers The group is on track to roll out 850 Co-op own-brand product lines to Nisa-supplied stores by the end of this year.

Nisa has also provided an update on its trading for the two months ending July 2018, as it brings its financial reporting year in line with Co-op Group.

Sales at the symbol group were up £9m to £263m and Nisa revealed that 71% of Nisa partners now stock the Co-op own label. This figure is expected to increase as phase four of the initial roll out of Co-op own brand products is launched in November.

Nisa Retail ceo Ken Towle said: “Nisa has traded well in the period under review, and I am pleased to be reporting improved sales and strong partner recruitment. We remain well placed to help our partners grow as they continue to evolve and improve the products they sell.

”Convenience customers are demanding higher quality products and, with this in mind, I am pleased to report that the initial wave of Co-op own brand product has been well received in the communities we serve. It has been a busy period since Nisa became part of the Co-op family, but I am excited about Nisa’s future and believe we have the scale, vision and ambition to succeed.”

Commenting on the Co-op’s results, Co-op chief executive Steve Murrells said: “We’re moving forward at pace with our Stronger Co-op, Stronger Communities plan, which we set out at the beginning of the year. We know that in order to make a difference, we have to be commercially successful and our performance in the first half shows that we’re delivering on that ambition. Our investment in products, price and distribution channels has seen us grow revenue, profit and member value in the first six months.

“We are also back to responding quickly and decisively to the issues which affect our members and customers. Funeral affordability is clearly an issue affecting many and our guarantee not to be beaten on price re-affirms our commitment, as market-leader, to also lead the market. Furthermore, our acquisition of Dimec allows us to accelerate the development of our healthcare proposition, and provides the digital platform required to help customers in the future conveniently access and link their healthcare needs, including interacting with their NHS GP.”

Co-op non-executive chair Allan Leighton added: “Against a backdrop of increasing national uncertainty, I’m pleased that the Co-op has continued to perform successfully during the first half of the year. It is in these times of volatility that our way of doing business, which gives back to our members and the communities we operate in, becomes even more important. These results show that we are growing our business and increasing the positive impact we can have on our members and the causes they care about in their communities.

“We’ve got exciting plans to continue transforming our Co-op to make it even more competitive, relevant and innovative in both existing and new markets. We’ll continue to grow our current businesses and through our Ventures team we’ll move into new areas where we can deliver even more value for our members and their communities.”

During the first half of this year, the Co-op invested £50m in improving its food prices across hundreds of everyday products. Industry CO2 shortages failed to impact beer, wine and spirit sales at the group, which increased 4.8% in the first half of this year.

Co-op Food also enjoyed a strong summer performance, while pay-in-aisle technology trials and self-delivering robot trials have also been introduced in selected stores.