M&S shares tumble by a third as traders wipe £1.7 billion off troubled retailer's value

The retail giant - reeling after last week's shock profits warning - saw shares fall 4% after two more analysts warned over the difficult outlook faced by the firm.

M&S, which already faces a rough ride from investors at its annual meeting on Wednesday, has seen its shares fall by a third since the warning, lowering its stock market value by around £1.7 billion.

High Street giant Marks & Spencer has reported a big drop in sales in the last three months

Its current £3.4 billion stock market capitalisation is just half that of value-end supermarket Morrisons.

The group's profits for the year to March topped £1 billion for the first time in a decade, but Pali International's Nick Bubb expects this to fall to £700 million this year.

Philip Dorgan of Panmure Gordon was even gloomier, forecasting £626 million.

Both highlighted the problems with M&S's premium-end food business as shoppers struggling with rising food prices rein in their spending.

The head of the group's food business, which has seen a "significant weakening" in the past three months, left last week after little more than a year with M&S.

"It is going to be a tough job to regain market confidence, let alone turn the food business around," Mr Dorgan said.