Grocery sales rose by 3.9% in the four weeks leading up to September 4, market data  company Nielsen has reported.

Co-op was the sector leader in the last quarter, delivering a year-on-year sales increase of 16.6%. Iceland also continued a good run, generating overall growth of 12.8%. Hard discounters Aldi, Lidl and Netto managed a year-on-year sales change of 12%.

John Lewis-owned grocer Waitrose achieved a 9.9% advance over the quarter, and Marks and Spencer’s sales climbed 7.1%.

“Increases have been driven by existing customers spending more when in store,” said Nielsen retail senior manager Mike Watkins.   

“All of the top four had fewer shoppers in August but an increased frequency of visit, which suggests the weather, promotion cherry picking and back to school visits have been the key drives over the summer.  The competitive landscape is certainly getting tougher in the run up to Christmas.”

But Watkins also said that unit sales have dropped back to 0.5% in the four weeks to September 4 “despite an increase in promotional activity and some strong back to school promotions”.

Food price inflation helped increase headline sales in the period.

Retailer12 weeks ending
5 Sept ’09
12 weeks ending
5 Sept ’09
% sChange
Co-op and Somerfield8.77.9-5.3