The Co-operative Group has reported like-for-like sales fell 3.2% in its food division for its fourth quarter, saying the weather took its toll on footfall and spending patterns.

For the 13 weeks to January 1, the Co-op said the planned acceleration programme to convert Somerfield to Co-op fascias also had an effect, as during the period around 200 stores were closed on average for seven days at a time for full refits.

Despite this, the retailer said its core convenience estate, including both Co-op and Somerfield stores, reported like-for-likes up 2%.

Group chief executive Peter Marks said: “The exceptionally cold weather created logistical issues for our food stores – particularly given the sheer scale and geographic spread of our estate. Our people worked exceptionally hard to ensure that we provided a great service to all our customers – and the strong performance of our core convenience estate is a testament to all their efforts.

“The planned acceleration of the Somerfield conversion programme was an added issue – but this continues at pace and we remain on track to complete the process by Spring 2011.”

Across the entire retail group excluding financial services, like-for-like sales fell by 0.6%.

The group’s non-food businesses were up 12.1% like-for-like, and it said it reported a strong performance in online electrical, motor and travel.