US doughnut and coffee retail chain Dunkin' Donuts is to launch a new line of espressos which will use Fair Trade coffee.

The espresso-based beverages, which will include espressos, lattes and cappuccinos, are to be launched in 800 outlets in the Boston and Providence, Rhode Island, area by September, with expansion to the New York Metropolitan area planned for January.

Dunkin’ Donuts’ plan to use only Fair Trade coffee in its espresso range means it will become one of the top buyers of Fair Trade beans, along with Equal Exchange, Green Mountain Coffee Roasters and Starbucks.

"We are projecting our purchases of Fair Trade coffee to equal about two percent of our buying," Rob Stephen, manager of coffee product development, was quoted as saying by Reuters.

Fair Trade certified products guarantee that farmers are paid a fair price for their products.