The California Public Employees’ Retirement System is losing another key executive to the private sector. This time, Fred Buenrostro, CEO of the nation’s largest public pension fund, has set his retirement from CalPERS for the end of the fiscal year.

Buenrostro said he intends to pursue professional opportunities in the private sector, CalPERS’ president Rob Feckner said the system’s board of administration will discuss naming an interim CEO at its May Board meeting while it searches for a permanent replacement.

Last month, CalPERS investment chief Russell Read announced his plan to leave at the end of June to “pursue his long-standing interest” in investing in clean and green technology companies.

Buenrostro is the system’s seventh CEO since its establishment in 1932.