Sainsbury's market share increased by 0.4 percentage points to 15.9 per cent, while Asda's share dropped by 0.1 percentage points to 16.5 per cent in the three months to May 22 compared to the same period last year, according to the latest TNS data.
TNS Superpanel communications director Edward Garner said: 'This represents real turnover growth of 5 per cent [from Sainsbury's] and confirms the solidity of the recovery.'
Tesco's stake jumped 2.3 percentage points to 29.9 per cent as the UK shopper's grocery expenditure for the three months to 22 May 2005 topped£17.3 billion, up nearly£500 million from the same period last year.
The combined stake of Morrisons and Safeway has dropped 2.2 percentage points to 12 per cent, as the group struggles with its merger of the two businesses.
Somerfield increased its share by 0.1 percentage points to 5.9 per cent, as the growth at its eponymous chain mopped up declines at Kwik Save.
Waitrose and Netto increased their share compared with last year while Aldi and Lidl's share remained the same.
But Iceland, the combined Co-ops and independent grocers all lost market share.