105.692.  Shares of common stock, voting requirements. — 1.  All shares of common stock held directly by a system, as defined under section 105.687, shall be voted solely in the economic interest of plan participants.  Voting shares for the purposes of furthering noneconomic environmental, social, political, ideological, or other goals is prohibited.

  2.  A system shall vote all proxies associated with its directly held shares of common stock by one of the following methods:

  (1)  By internal system staff; or

  (2)  By an investment manager or proxy voting service provider who has committed in writing to vote the shares pursuant to proxy voting guidelines chosen by the system or has committed in writing to vote the shares in a manner consistent with the obligation to act solely in the economic interest of plan participants.