Convenience stores are outperforming larger supermarkets in terms of sales growth, according to two new pieces of market analysis.

The latest Kantar Worldpanel snapshot of the market for the 12 weeks to 21 May shows total till roll, which includes all expenditure through main store tills, excluding petrol and in-store concessions, surged 7.1% to £517m in symbols and independents.

This demonstrates a trend for 2017 which has seen symbols and independents grow again after consistently seeing till roll totals shrink – by as much as 10.2% in the period to 9 October 2016.

Tesco, Sainsbury’s, Asda’s and Morrisons’ till roll growth for the current period was 1.8%, 1.7%, 0.9% and 1.9% respectively. The Co-op’s till roll climbed 1.5% to £1.598bn.

Overall grocery market sales grew 3.8% year on year – the market’s best performance since September 2013, outstripping grocery inflation which stands at 2.9% for the period.

The two big discounters, Aldi and Lidl, together grew at their fastest rate since January 2015. Their combined sales rose 19.2% year on year to achieve a record market share of 12%.

Own label, which has been a major area of focus for the affiliated independent sector, proved a major source of growth for all retailers, with sales up 6% year on year in contrast to branded products which grew by just 0.6%.

Chris Hayward, consumer specialist at Kantar Worldpanel, said the Co-op’s 1.5% growth was driven in part by strong premium own label growth.

“Sales of its ‘Irresistible’ range were up 33.7% year on year. The grocer also enjoyed its 25th consecutive period of overall sales growth, although its market share dipped by 0.2 percentage points” to 6%, he said.

Iceland grew well ahead of the market with sales up 8.6%, boosting its market share by 0.1 percentage points to 2.2%.

Separate research from Nielsen shows that the supermarket groups’ convenience stores are giving them an “inherent” advantage over the discounters with 26% of all grocery sales now going through convenience stores.

Mike Watkins, Nielsen’s UK head of retailer and business insight, said: “Although discounter growth continues through new store openings, the supermarkets still have a wider variety of formats, including online and local convenience stores, giving them a lot of scope to grow basket spend around different shopper missions.”