IRISH retailer Dunnes Stores is now the favourite supermarket south of the border but the major British chains remain dominant in Northern Ireland.
The latest figures from industry analysts Kantar Worldpanel show Dunnes now has a 22.6 per cent share of the market in the Republic - more than any other grocer.
Another indigenous retailer SuperValu is the second most popular on 22 per cent market share.
But while both grocers operate in the north - albeit under a different retail model - their share is swamped by that of the big three UK chains.
Tesco was Northern Ireland's favourite supermarket in the year to November 6 with a 34.8 per cent share of the market (more than its two main rivals combined).
It was followed by Sainsbury (17.4 per cent) and Asda (17.3 per cent).
Kantar Worldpanel director David Berry said Dunnes' performance south of the border was "largely down to its continued success in encouraging larger shopping trips via its Shop & Save promotional campaign".
"Persuading shoppers to add one extra item to every basket - worth €3.20 on average - may not sound like much, but across the country this adds up to an additional €2.8 million each week.
"Growth across a wide range of categories has contributed to the retailer’s overall sales increase of 6.7 per cent year on year, with toiletries, alcohol, frozen food and confectionery performing particularly well.”
Dunnes has in the past has been linked to a sale to either Asda or Sainsbury's.
If Asda or Sainsbury were to buy the company, it would give them a massive foothold in the Republic, where they currently have no presence.
Earlier this month, Dunnes Stores (Bangor) Ltd reported an 18 per cent jump in profits.
The Newry-registered firm had pre-tax profits of £13.2 million for the year to January 2016, compared to £11.2m over the previous 12 months.
However, turnover slipped 7 per cent to £127.6m as the company closed a number of stores in Northern Ireland.
