Investors have shied away from the Pizza Express restaurant group.

The shareholder distaste for the pizza chain came after the firm warned that its customers were not spending as much as it had hoped.

Pizza Express targets financial and media workers, two sectors which have been badly hit by the economic downturn.

Till now, its weakness in London has been countered by a solid performance elsewhere, but now sales are slowing nationwide.

The restaurant chain has also suffered from a run of bad publicity over comparisons with cheaper rivals such as Pizza Hut.

By the close, Pizza Express shares had lost 16.3% of their value to end at 513.5 pence.

Staying home instead

Chief executive David Page said the firm, which sells over 500,000 pizzas a week, had been a victim of its own success.

The cheaper spending habits of pizza-eaters has meant that 130,000 of the chain's pizzas are snapped up in J. Sainsbury every week.

"That's three times what we expected, and it's had a knock-on effect on our restaurants," said Mr Page who started working at the chain as a waiter.

Analysts have also pointed to more fundamental worries about market saturation and customer fatigue with the menu.

"This is my third profit downgrade this year," said Andrew Saunders of Numis Securities, cutting his full-year forecast to �39m ($59m) from an original �48m.

The British restaurant warned that its sales in the second half of the year would fall by 1%.