Upmarket grocer Waitrose grabbed a record share of supermarket sales last month as shoppers sought stay-at-home treats in the economic gloom, figures revealed today.

Waitrose saw its market share rise to 4.3% in the 12 weeks to February 21 from the same period a year ago as the firm also upped store numbers, according to the latest data from industry researcher Kantar Worldpanel.

The rise came amid a tussle for shopping spend between Tesco and Asda, the top two supermarket players, which have both boosted customer loyalty schemes recently.

John Lewis Partnership-owned Waitrose saw the second-highest rate of year-on-year sales growth, at 15.5%, after Co-operative’s 16.3% rise, which was boosted by the integration of Somerfield.

Fraser McKevitt, Kantar Worldpanel retail analyst, said Waitrose had chipped away at market share mainly from Sainsbury’s and Marks & Spencer, but also attracted casual custom from Tesco and Asda.

“They have opened a lot of new stores, which have helped their sales figures. It has made a Waitrose accessible to much more of the population,” he said.

“They have managed to prove that even in a recession the search for value doesn’t necessarily mean buying the cheapest.

“With people not eating out that much there is more of a willingness for people to spend money on eating in.”

But he said the firm might find it hard to keep up the momentum of recent gains.

“It is going to be very difficult for them to continue growing at the same double digit rate,” he said.

“But they have quite a lot of headroom in the sense that they do not have nearly as many stores as their competitors.”

Tesco’s market share was 30.4% last month, up from 30.1% in February 2009, which Kantar said had put pressure on Asda to up its customer promotions.

Asda – owned by US firm Wal-Mart – saw its market share dip in January for the first time in two years and the firm was again lower against 2009, with a share of 17% in February, compared with 17.2% last year.

Kantar said Tesco had “turned up the heat” on its closest rival with its Clubcard and double points customer promotions, but said the effects of Asda’s own coupon scheme had yet to be felt.

Market research firm Nielsen today said sales in the grocery market were subdued in the four weeks to February 20 for the second month in a row.

Year-on-year growth in grocery multiples fell slightly to 2.3% in the period and the firm said the figures confirm that any recovery will be long and slow, as well as reflecting the fall-off in food inflation, so values are no longer being driven up by rising prices.

Mike Watkins, senior manager of retailer services at Nielsen, said promotions in February stood at 34%, which is similar to that usually seen at key seasonal trading periods.

“Despite this, sales have remained subdued,” he said.

“Some retailers have been relying on seasonal events such as Valentine’s or Chinese New Year to drive sales up.

“We expect to see further activity like this and also more use of tactical deals as we approach Mothering Sunday. And thereafter the Easter promotional activity will really kick in.”