Top officers of the largest U.S. pension fund want to lower their investment targets, a move that would trigger more pain for cash-strapped cities across California and set an increasingly cautious tone for those who manage retirement assets around the country.

Chief Investment Officer Ted Eliopoulos and two other executives with the California Public Employees’ Retirement System plan to propose next Tuesday that their board abandon a long-held goal of 7.5% annually, according to system spokesman Brad Pacheco. Reductions to...