ST. LOUIS — Ron Shaich, founder and executive chairman of Panera Bread Co., and Bill Moreton, president and chief executive officer, will become co-chief executive officers of Panera, effective immediately

Panera said the transition to co-CEOs formalizes a relationship that has evolved over the past year and is a reflection of the way in which Shaich and Moreton have been operating as partners. Moreton, who joined Panera in 1998, succeeded Shaich as president and CEO in May 2010. At that time, Shaich was named executive chairman and said he planned to “take what I have learned at Panera to the broader world.” Shaich began his career in the bakery-cafe industry in 1981 and went on to co-found Au Bon Pain Co., Inc. and, ultimately, co-found Panera Bread.