Morrisons reported a rise in sales in the Christmas shopping period, while the market share of discounters Aldi and Lidl reached its highest-ever level for the festive season.
David Potts, chief executive of the number four supermarket chain, said customers were “increasingly savvy”.
While the business was getting ready for Brexit, he said two-thirds of the produce it sold was from the UK.
Morrisons’ sales rose 3.6% in the nine weeks to 6 January.
This increase in like-for-like sales, which strips out new store openings, was driven by a 3% rise in the wholesale division, which supplies Amazon and McColls.
In the stores, sales rose 0.6% – more than the 0.5% expected by analysts – but there was a slowdown from the 1.3% in the third quarter and the 2.1% reported last Christmas.
Its shares were the biggest fallers in the FTSE 100, down nearly 4%.
Even as the company maintained its outlook for the 2018-19 financial year, Richard Hunter, head of markets at interactive investor, said Morrisons remained under pressure from rivals in the so-called ‘big four’ and the discounters.
“A resurgent Tesco, the proposed Asda/Sainsbury alliance and the continuing advance of Aldi and Lidl all add to a challenging environment,” Mr Hunter said.