Jan. 10 (Bloomberg) — Joseph Dear, chief investment officer of California Public Employees' Retirement System, the largest U.S. public pension plan, is taking leave to continue personal health treatments.

Ted Eliopoulos, current senior investment officer for real estate, will serve as acting CIO of the more than $277 billion pension plan, also known as CalPERS, spokesman Brad Pacheco said in an e-mailed reply to a Bloomberg News query. Dear, 62, isn't stepping down, Pacheco said, adding that he has no timeframe for Dear's medical leave. Dear will continue to periodically attend meetings and calls to "provide his expertise on important issues," Pacheco added.

Dear took over as CalPERS CIO in March 2009, about two months after fund assets hit a recession low of $164.7 billion, 37 percent off the October 2007 peak. Under him, assets have rebounded even as investment results have remained volatile in the past five years.