Two of the big four supermarkets are feeling the pressure of market share, as discount retailers continue to increase grocery sales.

The latest grocery share figures from Kantar Worldpanel for the 12-week period to 28 October 2012, published today, revealed a 0.5% drop in market share for both Tesco and Morrisons year-on-year to 30.5% and 11.5% respectively.

Aldi continued to make its stamp on the market by reaching an all-time record high of 3%, with Lidl experiencing a 0.2% lift year-on-year to 2.7% and Iceland moving up by 0.1% to 2% for the 12-week period.

Edward Garner, director at Kantar Worldpanel, said: “Morrisons’ performance this month will cause concern, with its share dropping from 12% to 11.5% and a decline in sales of 0.4%. Recent announcements about the development of online and convenience, which are the two fastest-growing grocery channels, will no doubt be given added urgency as these channels continue to deliver growth for competitors.”

Kantar Worldpanel said Sainsbury’s, which last month reported a 4.3% lift in sales for the 16 weeks to 29 September 2012, was the “stand-out performer” during the 12 weeks, as it increased its market share by 0.4% to 16.8% compared to the same period last year.

Asda remained level at 17.5% year-on-year and Waitrose managed to boost its position within the grocery sector with a 0.2% increase to 4.7%.

Grocery inflation for the same 12 weeks stood at 3% – a 0.4% rise on the same period last year – which Kantar Worldpanel believes will continue to increase in the future, due to high food prices on an international scale working their way through to retail channels.