VALLEY FORGE, Pa. — David Yost officially handed the reins of AmerisourceBergen to Steven Collis, who was named president and CEO on Friday, as Yost prepares for retirement.

"On behalf of our entire company, I thank Dave for his 37 years of extraordinary service to AmerisourceBergen, and for his gracious support during the leadership transition," Collis stated. "I believe with our momentum, our position in growing markets, our talented and seasoned management team, and our dedication to efficiency and innovative customer service, we will continue to drive success by growing our business and providing value to our customers, suppliers, shareholders and our associates."

Collis previously served as president and COO, responsible for all AmerisourceBergen business units, including AmerisourceBergen Drug Corp., AmerisourceBergen Specialty Group, AmerisourceBergen Consulting Services and AmerisourceBergen Packaging Group. Before being promoted to that position in November 2010, Collis was AmerisourceBergen EVP and president of ABDC, the company's largest subsidiary with revenues of more than $60 billion.