Shrek works like a charm for Mickey D's

NEW YORK (CNNMoney.com) -- McDonald's on Friday posted strong U.S. sales in May, helped in part by the big green ogre "Shrek."

The No. 1 fast-food chain reported that sales at its stores open at least a year - a key measure of retail performance known as same-store sales - jumped 7.4 percent in the United States and 11.9 percent worldwide.

McDonald's scores a hit with its new 'Shrek' Happy Meals.

In the U.S., McDonald's said its "Shrek the Third" promotion and breakfast contributed to last month's strength.

In early May, McDonald's (Charts, Fortune 500) and DreamWorks Animation (Charts), the studio behind the "Shrek the Third" movie, unveiled a promotion in which Shrek, Donkey and other characters from the animated film were the theme of the new Happy Meals and other McDonald's food.

But unlike previous movie tie-ins, McDonald's decided to use Shrek to feature healthier food items like its salads, milk, apple slices and other products introduced in the last three years as the burger chain tries to combat mounting criticism that its food is contributing to the obesity epidemic in both kids and adults in the United States.

In Europe, McDonald's said same-store sales rose 8.9 percent, boosted by favorable response to the recent launch of Chicken Selects and Snack Wrap in Germany and limited-time offerings of premium chicken and beef sandwiches in France and the U.K.

"Around the world, demand for McDonald's continues to grow as we now serve 6 million more customers every day than we did in 2002," McDonald's CEO Jim Skinner said in a statement.

"We are working to attract more customers, more often, through innovation, added convenience and greater menu choice to capture a larger share of the growing eating-out market," he said.