"They get into the market in a big way when they do it," said Chicago-area retail consultant Rich Kizer of Tesco's aggressive approach to staking territory. "These guys come in and they come in serious."

By comparison, Fresh & Easy competitors Trader Joe's and Whole Foods have five stores combined in the Las Vegas Valley.

In addition to eschewing tobacco products and foods with trans fats and artificial ingredients, Fresh & Easy aims to make shopping easier by operating stores that are smaller than traditional supermarkets.

Each of the Fresh & Easy stores will have about 10,000 square feet of space, compared with as much as 150,000 for a major supermarket. The smaller size makes the stores more manageable for older customers, said Kizer and his partner Georganne Bender.

It's a store style popularized by chains such as Trader Joe's.

Bender said there are 64 million members of the baby boom generation and 76 million people age 65 and older who are likely to prefer smaller stores with higher-quality, healthier groceries.

"Those two generations of people are merging together," Bender said. "That is going to be a perfect store for them."

Brendan Wonnacott, a California-based spokesman for Tesco, said it is too early to know when the stores will open. But he expects more Fresh & Easy stores will follow the initial 15 in Las Vegas.

Tesco operates more than 2,800 stores in 12 countries and employs 370,000 people. It has operated under the Tesco name since 1929. The company's innovations include the introduction of a grocery club card and the world's largest Internet grocery store, Tesco.com. It has stores in Ireland, the Czech Republic, Hungary, Poland, Slovakia, Turkey, China, Japan, Malaysia, South Korea and Thailand.