Sainsbury's has reclaimed its place as the UK's second largest grocery.

The supermarket took over from Asda in top spot for the first time since January.

It came against a backdrop of falling sides, with a slide of 0.3 per cent during the 12 weeks to to July 19.

Growth was driven by non-food sales and faster growth at its convenience stores in south east of England, where it has a large number of stores, according to independent analysis of the latest till roll figures.

Its market share also dipped from 16.6per cent to 16.5per cent in the period.

Asda was the biggest faller of the major supermarkets, seeing its sales fall 2.7per cent, and its market share slip from 17per cent to 16.4per cent.

Meanwhile, the Co-operative grew sales for the first time in a year, marking a highlight in a troubled two years for the group, according to the research by Kantar Worldpanel.

The troubled Co-op group increased sales by one per cent boosted by its expansion into convenience stores.

The chain returned to growth for the first time since July last year, although its market share remained at 6.3per cent.

The Co-op bank nearly collapsed in 2013 and dragged the wider Co-operative group to a £2.5 billion annual loss that year, after a £1.5 billion hole was discovered in the lender's balance sheet.

Fraser McKevitt, head of consumer and retail insight at Kantar Worldpanel, said: "The Manchester-based grocer's focus on its convenience offer has been rewarded with an increase in shopper numbers, which have risen by 133,000."

Overall, Kantar said supermarket sales rose 0.8per cent year-on-year across the sector, with growth and record market shares coming from smaller grocers as the UK's Big Four supermarkets all suffered falls.

The UK's major chains have fought a intense price war against discounters such as Aldi and Lidl over the last year. The falling price of stables such as eggs and bread, mean that the average grocery basket costs 1.6per cent less than last year.

By contrast, Aldi grew by 16.6per cent while Lidl saw growth of 11.3per cent, meaning both chains moved to record market share highs of 5.6per cent and 4per cent respectively.