The Co-operative Group has reported a 0.7% decline in full-year like-for-like sales in its food business.

In what CEO Peter Marks described as a “challenging year” for the society as a whole, underlying profits in the food business fell 9.5% to £288m, on sales up 1.4% to £7.44bn in the year to 5 January.

Food had shown a “marked improvement” throughout the year, Marks said. Although like-for-likes were down by as low as 2.2% in the second quarter, in the fourth quarter of the year they recovered to +0.3%.

“Our investment in IT and the supply chain helped us to reap the benefits of our focus on customer value and service and consistent execution,” Marks said.

“Our focus has been on improving the shopping experience by tailoring stores to our customers and locations. Our investment thinking for 2013 has been shaped by the delivery of 60 format trial stores, which have received great customer feedback and encouraging sales figures.”

Overall group underlying profits dropped 89% to £54m, hit by a number of factors within its banking business. Group sales rose 1.5% to £13.5bn.

The group also announced plans to sell its general insurance business. Earlier this week, it sold its life insurance and asset management business to Royal London for £219m.