NEW YORK - First there were McNuggets. Then there were Chicken McBites. Now McDonald's could be adding "Mighty Wings" to its chicken menu.

The world's biggest hamburger chain is set to expand its test of chicken wings to Chicago this week, after a successful run in Atlanta last year. The wings are being sold in servings of three, five or 10 pieces with prices starting at $3, according to Lynne Collier, an analyst with Sterne Agee.

A spokeswoman for McDonald's confirmed the test in Chicago would start this week at 500 restaurants but said there weren't any plans yet to bring the wings to other cities. She noted that no new sauces were being offered with the wings and that the creamy ranch sauce would be the default dipping sauce.

Fast-food chains typically test items in select markets before taking them national. But for McDonald's, which has 14,000 U.S. locations, adding chicken wings to the permanent lineup could be tricky.

Prices for chicken wings have been climbing over the past year, reflecting an increase in the number of restaurants serving them, said David Harvey, an agriculture economist who specializes in poultry and eggs at the U.S. Department of Agriculture. In December, the cost of wings in the wholesale market in the Northeast was 26 percent higher than a year ago. Wings sold for $1.90 a pound that month, compared with $1.30 a pound for boneless, skinless chicken breasts.

And prices could continue to climb with demand remaining high, pressuring prices for wings across the industry.

Rather than becoming a permanent part of the menu, McDonald's could offer the dish for a limited time; the chain has said it plans to ramp up the frequency of such special offers as a way to give customers more variety. But whether it will offer "Mighty Wings" even on a limited-time basis will likely depend on McDonald's ability to get wings at reasonable prices, said Collier, the analyst with Sterne Agee.

There could be other challenges. Richard Adams, a former McDonald's franchisee who now runs a consulting firm for franchisees, said that menu items generally don't work unless they can be eaten easily in the car. He noted that the majority of McDonald's food is purchased at the drive-through.

This isn't the first time McDonald's is offering wings, however. According to the National Chicken Council, McDonald's first introduced them in 1990 at some locations, prompting other fast-food chains to follow suit. A McDonald's representative wasn't able to immediately provide the history of "Mighty Wings."

The latest test comes amid intensifying competition for McDonald's, which for years had outperformed rivals such as Burger King and Wendy's with a steady stream of new menu items, such as snack wraps, fruit smoothies and specialty coffee drinks. But now Burger King and Wendy's are working to revamp their images and menus.

This past spring, Burger King launched its biggest ever menu expansion to include its own snack wraps, fruit smoothies and specialty coffee drinks. And last week, the Miami-based chain even introduced chicken nuggets that more closely resemble McNuggets, replacing the chicken tenders it previously sold.

In addition, McDonald's is facing competition from newer chains such as Chipotle Mexican Grill Inc. and Panera Bread Co., which serve higher-quality food for slightly higher prices. In October, McDonald's said a key sales figure dropped for the first time in nearly a decade. The figure rebounded in November after the Oak Brook, Ill., company said it would return to emphasizing its Dollar Menu to lure price-conscious diners.