The California Public Employees’ Retirement System, the largest U.S. pension, is developing plans to shift as much as $30 billion from external to internal managers as it seeks to reduce fees. The $306 billion system now oversees about 70 percent of its assets internally, most in stocks and bonds, a share that can increase as Calpers develops capacity to handle private equity, real estate and infrastructure, according to Chief Investment Officer Ted Eliopoulos.