Supermarkets still account for two-thirds of BWS sales and saw value sales rise 2.7% to £9.5 billion, but volumes dropped 0.2% as convenience stores ate into market share.
IRI analyst Steve Jones said: “By the end of 2013 there were 10% more multiple convenience stores than in 2012 – that’s been the focus of their real estate portfolio.
“People are shopping little and often to keep spend down and economic conditions, smaller households and longer working hours are increasing convenience shopping occasions.”
Symbol groups such as Bargain Booze, Spar and Londis also enjoyed healthy growth, with volume sales up 3.4% and value sales up 5%. But independents struggled, with volume down 2% but value up 2.2%.
Petrol station forecourts now account for £400 million of BWS sales, up 4.2% in value and 2.1% in volume in the past year.
IRI also revealed the BWS market has returned to volume growth, rising 0.9% in the year to March 1, and also climbing 3.7% in value to £14.5 billion.