The data, from ACNielsen Homescan, shows a growth in market share from 3.4% in the 12 weeks to October 2 last year to 3.7% in the 12 weeks to June 11.
Waitrose has itself also reported double-digit sales growth as it nears its half-year. Sales rose almost £10m to £64.62m in the 20 weeks to June 18 this year, compared with the same period last year.
Recent increases were driven
by Father’s Day and good weather, which boosted suncare, salads, soft drinks and fruit sales.
Separately, there are signs of the supermarket’s increased willingness to throw its weight behind the campaign to extend Sunday trading hours.
“If there were a move to extend the window of legal Sunday trading we would support it,” said Andy Street, director of personnel for the John Lewis Partnership. He said Sunday was a popular shopping day for Waitrose and John Lewis customers.
Waitrose has also struck a deal to supply Thailand-based retailer Tops with 80 own-label products, from jams to organic flour. The lines will be exported to 24 Tops supermarkets, including shops in Phuket, Pattaya and Samui.
Waitrose is already supplying own-label lines to supermarkets operating in Singapore, Hong Kong and Brunei.