Tesco increased its share of the grocery market by 1 per cent in the past three months, while Sainsbury’s is on track to leapfrog Asda to become the UK’s second largest supermarket, according to TNS Worldpanel. Tesco increased its market share from 30.4 per cent to 31.4 per cent over the 12 weeks to December 31 year on year, based on an 8.4 per cent increase in till roll sales. Sainsbury’s share of the market jumped from 16.2 per cent to 16.4 per cent over the same period, putting it in the rear view mirror of Asda’s 16.6 per cent. Asda’s market share flatlined over the 12 weeks, although it also increased till roll sales. Waitrose also increased its market share from 3.7 per cent to 3.9 per cent, on sales up an impressive 10.6 per cent.