California Public Employees' Retirement System or Calpers Chief Investment Officer Joseph Dear is taking a medical leave to proceed with his personal health treatments, Bloomberg reported. Calpers is the biggest public pension plan in the US. In an emailed reply to the questions of Bloomberg News, Calpers Spokesman Brad Pacheco said the company's current senior investment officer for real estate Ted Eliopoulos will act as the CIO of the pension plan while Dear is on leave.

Pacheco said 62-year old Dear is not stepping down from his post and that no timeframe is given for his medical leave. Dear will still attend meetings and calls periodically so he can give his expertise on important matters, Pacheco said.

Dear became the CIO of Calpers in March 2009, just two months after the assets of the fund plunged to a recession low of $164.7 billion. This was 37% decline from the high reached in October 2007. The report said assets recovered under his leadership despite the continued volatility of investment results in the past five years.

Bloomberg reported that after posting record losses in the worldwide economic crisis, public pensions have been feeling the pressure to increase its investment returns. For the fiscal year that ended in June 30, Calpers was able to post a gain of 12.5% on its investments with the rise of global stock indexes. In 2009, it lost a record 23% but rebounded in 2011 when it gained nearly 21%. The year after that, Calpers earned 1%.

In June, the Calpers announced that Dear was relinquishing some of its daily investment operations to Eliopoulos as he undergoes treatments for prostate cancer. Pacheco said last year that Eliopoulos had restructured the pension fund system's property holdings so it could concentrate on assets that produce income and bring down related debt, the report said.