Rick Dahl, chief investment officer of the $9 billion Missouri State Employees' Retirement System, Jefferson City, will retire in the first half of 2016, said spokeswoman Candy Smith.
A specific date has not been determined, Ms. Smith said. Seth Kelly, the pension fund's deputy CIO, will succeed Mr. Dahl.
Shannon Davidson, the pension fund's risk and operations manager, will succeed Mr. Kelly as deputy CIO.
Mr. Dahl has been the pension fund's CIO for 21 years. He could not be reached for comment.