Oak Brook, Illinois--McDonald's Corp. Chairman and CEO Jack M. Greenberg, who has been under fire for the fast-food chain's weak performance, has announced his retirement after 21 years with the company. Jim Cantalupo, former vice chairman and president, becomes McDonald's fifth chief executive when Greenberg departs December 31.

McDonald's, a powerhouse through the '80s, has stumbled in recent years, as the U.S. fast-food market became saturated, consumer tastes began to shift and fears of mad-cow disease decimated European sales. Greenberg, who earlier this year said he would stay on until 2005, had devised several plans to improve results--most notably the costly Made for You cooking system that was supposed to produce hotter, fresher meals but also created longer lines. -Crain's Chicago Business