The Bradford-based grocer has been trying to lure back shoppers by slashing prices and price-matching discounters Aldi and Lidl, but data from Kantar Worldpanel showed its market share fell to 11.2 per cent from 11.6 this time last year.
Tesco sales fell by 2.7 per cent, its smallest decline in sales since June, while Leeds-based Asda’s sales fell by one per cent and Sainsbury’s by 1.8 per cent, making them the best performers of the “big four”.
Aldi’s sales grew by an astonishing 22.3 per cent, taking its market share from 4.0 per cent last year to 4.9 per cent, while Lidl’s sales rose 18.3 per cent to give it a market share of 3.7 per cent, up from 3.1 per cent.
The data showed that shoppers have saved £182m on grocery offers in the past three months as supermarkets slashed prices in a bid to outdo each other and steal custom back from the discounters.
Kantar Worldpanel’s head of retail and consumer insight Fraser McKevitt said: “Britain’s supermarket price war is ramping up ahead of the all-important Christmas period.
“It’s not great news for the retailers, but it’s great news for the shopper.”
The market returned to 0.1 per cent growth as shoppers put slightly more goods in their baskets.
Mr McKevitt said Morrisons’ figures were hit by heavy vouchering and it has had teething problems with its entry into convenience stores.
“They have had a disappointing time with M Locals and have shut several,” he said.
“Running a convenience business is very different to running a supermarket. They have had to find out what ranges to put in and they’ve been learning as they go along. It’s clear that not all have worked. I imagine they have learned some hard lessons.”
He also said there is no sign of a real pick-up in sales since Morrisons launched its Match & More loyalty card which promises to match its three main rivals and Aldi and Lidl.
“I fear it could be a bit too complex,” he said.
“Match & More isn’t coming through in the numbers yet, but I think we will see Morrisons pick up in the next few months.”
He said the big question is whether Aldi and Lidl will retain customers over Christmas or whether shoppers will trade up for the all-important festive shop.
“Over the past 12 weeks, 54 per cent of shoppers have spent in a discounter. Christmas is focused around fresh, on the turkey and the vegetables, and this is an area where Morrisons are quite strong.
“We simply don’t know what will happen yet. People should have a bit more in their pocket this year.”
He said that despite the one per cent fall at Asda, it was still the best performer out of the “big four”.
“Even Asda aren’t immune to the 0.7 per cent fall in like-for-like prices. Also Asda are quite exposed to a Tesco recovery.”