The executive directors of Ohio's five state retirement systems sent a joint letter today to Gov. Bob Taft, state Senate President Doug White and state House Speaker Larry Householder, opposing "buy Ohio" investment and trading mandates for the systems and the state treasurer's "super-authority" over the retirement systems. The provisions are part of a House bill passed Nov. 13. It would require that 50% of the systems' externally managed assets and 70% of their brokerage trades go to firms with a significant presence in Ohio. The systems - Ohio Highway Patrol Retirement System, Ohio Police and Fire Pension Fund, Ohio Public Employees Retirement System, Ohio State Teachers Retirement System and Ohio School Employees Retirement System - have more than $115 billion in total assets.