CHICAGO (AP) _ McDonald's offered something new to its customers Friday - McExecutives.

Corporate offices shut down worldwide as thousands of McDonald's executives wiped tables, flipped burgers, whipped shakes and deep-fried fries at the company's 9,000 fast-food restaurants and franchises in 43 countries.

''It brings us back to our roots,'' said Paul D. Schrage, senior executive vice president and chief marketing officer for the Oak Brook, Ill.-based company.

Schrage, 51, stood shoulder-to-shoulder Friday with 18-year-old Carolyn Jones at a Chicago McDonald's, filling orders at the drive-in window.

''He's doing good. He learns real fast,'' said Ms. Jones.

The role reversal was part of this year's Founder's Day observance honoring longtime chairman Ray A. Kroc, who died in 1984. Under Kroc, McDonald's grew from a small chain of hamburger restaurants in 1955 into a landmark industry that generated $11 billion in sales in 1985.

Similar exercises - called ''Store Days'' - had been conducted for years on a spot basis, but Friday marked the first systemwide shift from the front office to the front counter, spokesman Chuck Rubner said.

Executive Steve Barnes, outfitted in a yellow visor and apron emblazoned ''McRookie'' in large red letters, glanced down at a typewritten schedule of chores.

''My first job is in the lobby, then next is fries, then the drive through, then the grill,'' said Barnes, 67, chairman of McDonald's international division.

As a lobby worker, he said his duties would include disposing of garbage left by customers and wiping tables. Then he would try his hand at turning hamburgers, preparing french fries and answering drive-in calls.

Barnes was waiting his turn at fast-food chores in the outlet north of Chicago's Loop along with four other executives and a McDonald's board member.

''I can't wait to see 'em,'' said employee Alicia Meeks, 18, of the high- ranking rookies.

The Founder's Day exercise ''takes staff who are not in the restaurants on a regular basis and reminds them of what goes on in the stores,'' said Schrage. ''It takes some of the blue sky out of programs and puts the practicality back in.''

McDonald's president, Fred L. Turner, was joining the rank and file at a suburban Chicago restaurant.