A. Schulman, a $1.6 billion plastics manufacturer in Akron, Ohio, said its controller, Donald McMillan, will take on the additional title of chief accounting officer. McMillan is also interim principal financial officer, a role he has been performing since Paul DeSantis left the company in February. Chief accounting officer is a new position for the company. McMillan, 51, has served as A. Schulman's controller since 2006, and has worked in finance throughout his 15 years with the company. Before joining A. Schulman, he worked in public accounting.

Black Hills Corp., a $1.3 billion energy company in Rapid City, S.D., named Brian Iverson treasurer and vice president. He replaces Garner Anderson, who continues to serve as chief risk officer and vice president. Iverson, 48, most recently was the company's vice president of electric regulatory services. Since joining Black Hills in 2004, he has worked in the legal, regulatory and resource planning areas. Prior to joining the company, he worked in law and banking.

Titan Machinery, a $1 billion maker of construction and agricultural equipment in West Fargo, N.D., named Mark Kalvoda CFO. He replaces Peter Christianson, who remains with the company as president and COO. Kalvoda, 39, has served as chief accounting officer since joining Titan in 2007. Earlier, he spent three years at American Crystal Sugar, including stints as controller and assistant treasurer, and worked in finance at Hormel Foods.