For all the grumbling about British food, one London restaurant chain, Pret a Manger, has won over many New Yorkers with its grilled chicken and avocado sandwiches, its brie-and-basil baguettes, and its range of soups, salads, smoothies, and sweets.

Seven years after expanding into New York, Pret is planning to quadruple the number of city stores by launching 33 new locations here within three years — in addition to opening shops in Boston and Washington. “If New York could support one on every corner, we’d love that,” the company’s chief executive, Clive Schlee, told The New York Sun.

Since London is home to 120 Pret locations — prêt à manger means “ready to eat” in French — New York, which is more populous, should be able to accommodate at least 100 shops, Mr. Schlee said. “New York is probably the most sophisticated food market in the world,” he said. “People there really appreciate our natural and organic food — and they really appreciate the speed of our service.”

Unlike many other restaurant chains, the company works with local farmers and vendors, and Pret’s offerings, prepared daily, contain no preservatives, artificial colors or flavors. Its meats are free from antibiotics and hormones, while its milk, eggs, coffee, tea, and juices are organic. That said, Pret is a fast food joint in its purest form: Customers can expect to wait on line there no more than 90 seconds.

Under its current expansion plans, most of the new shops would be concentrated between 35th and 57th streets, between Third and Seventh avenues, the president for the American market, Gerard Loughran, said, noting that office workers and shoppers are its target consumers. Additional Pret locations are also likely in SoHo, and in the Flatiron and Financial districts.

A Pret invasion, much like the Starbucks invasion of the last decade, could make it harder for mom-and-pop shops to compete. The executive vice president of the New York State Restaurant Association, E. Charles Hunt, said “there’s always room in the city for another good operation.”

Mr. Hunt called Pret’s projected growth “ambitious” — given New Yorkers wide range of sandwich options, from Cosi to Subway to corner delis citywide. “But there is something unique about Pret A Manger’s approach, because it’s totally fresh as far as the food is concerned,” he said.

Pret’s planned growth has been fueled by its success at its existing 11 stores in New York, where same store sales grew 23% last year, and where revenues totaled $18 million, according to data provided by the company.

Most Pret sandwiches range in price from $5 to $7. An “All Natural Slow Roast Beef, Arugula & Parmigiano” Pret baguette costs $6.76, which is almost $2 more than a six-inch roast beef sandwich at a Subway in New York.

“It might be pricier than others, but there’s a high satisfaction level,” a customer at Pret’s Broad Street location, Jennifer Coleman, 28, said yesterday. “The ingredients are fresh. I want to order everything every time I come.”

McDonald’s owns one-third of Pret, while the company ‘s founders, Julian Metcalfe and Sinclair Beecham, and some of its managers own the remaining interest. Asked if the shareholders would ever consider taking the company public, a company spokeswoman, Taryn Langer, said Pret executives were “always open to options that would help the growth of the company.”