California Public Employees’ Retirement System’s (CalPERS) senior portfolio managers, Joncarlo Mark and Michael Dutton, have resigned, Pensions & Investments reports. The two managers were associated with the system’s $47.5 billion alternative investment management (AIM) program.

Mark, who has been with CalPERS since 1999, helped in the development of the system’s private equity program, while Dutton ran its health-care investment initiative. The duo will leave the $226.5 billion system in March 2011 and their duties will be taken over by other staff in the AIM program.