ManpowerGroup Inc.’s (NYSE: MAN) Jonas Prising assumed the role of the CEO of the company, Jeffrey Joerres transitioned to the role of executive chairman and Darryl Green took over as the company's president and chief operating officer, effective May 1. Prising is only the fourth CEO for the company since it began in 1948. The world’s third-largest staffing firm announced the leadership changes earlier this year. Former CEO Jeffrey Joerres was to transition to the role of executive chairman, and he will continue to be active in the business.

Separately, Volt Information Sciences Inc. (OTCBB: VISI) is ending the employment of Howard Zimmerman, its chief operating officer, North America Staffing, effective May 9, according to a filing with the U.S. Securities and Exchange Commission. Zimmerman had been the COO of North America Staffing operations since November 2012, and he had been with Volt for 27 years, according to a separate SEC filing. He began at Volt as a branch manager in the company’s San Diego office. His other management positions included regional manager in 1989, vice president in 1991 and senior vice president in 2001. Before joining Volt, Zimmerman led sales organizations at Memorex, Texas Instruments and ADP from 1978 through 1987. New York-based Volt is the fifth-largest U.S.-based IT staffing firm.