John Mackey, chief executive of Whole Foods Market, said on Wednesday the high-end supermarket chain had reached “a tipping point” for sustained and rapid growth, as quarterly sales topped $1bn for the first time.

“All the indications are pointing to the fact that the Whole Foods Market brand has definitely hit tipping point,” Mr Mackey said. “We are building a record pipeline of new stores and have sufficient capital to grow as rapidly as we can...the brand continues to strengthen and we open bigger and better stores at an accelerated rate in the years ahead.”

Whole Foods’ sales at stores opened for at least a year increased by 11.6 per cent during the company's second quarter, while total sales increased 21 per cent to $1.1bn. Net income was up 25 per cent to $89.9m, with diluted earnings per share up 20 per cent at $1.33.

The retailer also increased its forecast for comparable store sales growth in the coming quarter to 9 to 11 per cent, from 8 to 10 per cent, and said it expected full year sales growth to be “at the high end” of its forecast of 15 to 20 per cent.

Mr Mackey highlighted the performance of the company's third new store in New York City, at Union Square, which he said had achiveved “amazing” results without any expenditure on marketing or advertising.

Whole Foods also said it hoped to finalise plans soon for a new large store in central London, to add to its existing eight Fresh & Wild brand stores in the UK, acquired in January last year.

“We think there are opportunities well beyond the UK ...in Ireland, the Netherlands and elsewhere. We think this is a long-term process, but that it will in the long term produce tremendous opportunities for the company,” said Lee Valkenar, executive vice president for global support.

The strong overall sales growth in the recent quarter was also supported by the retailer's continuing expansion of its store network and its use of larger stores, with the weighted average square footage of its 168 stores up by 13 per cent over the year.

Whole Foods has set itself a long-term growth goal of $10bn in sales by 2010, from $3.9bn in 2004, and currently has 59 new stores in development.

Mr Mackey also stressed Whole Foods Market’s emphasis on selling perishable foods, which currently account for over two thirds of its sales, saying he would not be surprised if the share of sales increased to 75 per cent.

Whole Foods’ focus on high quality presentation of fresh food is contributing to the reshaping of the US food retail business, bringing additional pressure on the large retail chains who are already facing increased low cost competition from Wal-Mart, Target and other discounters.

Safeway, which had annual sales of $18bn last year, is currently remodelling its stores to emphasise its fresh products, in a move that analysts see as a response to the challenge from Whole Foods.