NEW YORK - Pizza Hut plans to start offering pizza by the slice for the first time in two locations this week, part of a test to refashion its image and court diners in their 20s and 30s.

The chain says the two locations - one in York, Neb. and Pawtucket, R.I. - will open Tuesday.

A slice will cost between $2 and $3 and take three to four minutes to heat up. They'll be made with new recipes more in line with the thinner pies sold in the Northeast.

The tests reflect how established restaurant chains are scrambling to keep pace with a rapidly changing industry. Diners are increasingly flocking to places such as Chipotle, where they feel they can get restaurant-quality food for just a little more than they would pay at fast-food chains such as Burger King.

In fact, Chipotle recently announced plans to move into the pizza business with Pizzeria Locale. Customers walk up to a counter and can watch as their pizza is built; the pie is then placed in an oven that cooks it in about 2 minutes. Other pizza chains feature similar fast-cooking, make-your-own concepts, including Blaze Pizza, based in Pasadena, Calif., and Pizza Studio, based in Los Angeles.

For its part, Pizza Hut has been focusing on developing its smaller format carry-out stores rather than its dine-in restaurants in recent years as its sales have been choppy. In each of the first three quarters of 2013, sales fell slightly at locations open at least year.

"We're seeing the trends for quick and ready products," noted Carrie Walsh, Pizza Hut's chief marketing officer.

Rival Domino's has also been selling pizza by the slice at some of its newly designed stores, according to a spokesman. Pizza Hut's parent company, Yum Brands Inc., is also testing a more upmarket concept with its KFC chain called "KFC eleven." And McDonald's, the world's biggest hamburger chain, is testing a "build-your-own burger" concept in Laguna Niguel, Calif.

Some chains aren't currently built to deliver the type of dining experience being popularized by the likes of Chipotle. Pizza Hut's traditional ovens, for instance, take about 7 to 10 minutes to cook pies, according to Al Litchenburg, the chain's chief development officer. By comparison, the upstart pizza chains such as Blaze Pizza promise cooking times of just two to three minutes.

Litchenburg says the Pizza Hut test locations will be equipped new ovens to heat up the slices, but they'll also have the traditional ovens to cook other pies.

He said the company, which is based in Plano, Texas and has 6,400 U.S. locations, will test variations of the concept throughout the year before deciding how to proceed.

The test restaurant in Nebraska will have a modern design featuring exposed brick walls and metal accents. It will have salad and pasta stations; customers walk up and order their food, then have it brought to them by employees.

The smaller Rhode Island location will only feature the "slice bar." The slices there will be a bit thinner than in Nebraska to reflect local tastes, Litchenburg said.