Sainsbury’s said like-for-like sales excluding fuel fell by 0.7% in the third quarter.
The supermarket group said like-for-like trade in groceries rose by 0.4% in the 15 weeks to 4 January, while clothing sales rose by 4.4%.
However it recorded a sharp fall in general merchandise.
Sainsbury’s, which owns Argos, said like-for-like sales for general merchandise dropped by 3.9%
Chief executive Mike Coupe said: “Argos outperformed the market in consumer electronics, but the toy and gaming markets declined year on year.”