The nation's largest teacher pension fund took the first step Wednesday toward divesting from companies that make guns and high-capacity ammunition magazines that are illegal in California.

State Treasurer Bill Lockyer made a motion to begin the divestment process after pension fund officials determined that the fund invests in the owner of a company that manufactured one of the weapons used in the Connecticut school shooting. The California State Teachers' Retirement System's investment committee unanimously approved the motion.

CalSTRS has investments in private equity firm Cerberus Capital Management LP, which owns the manufacturer of an assault weapon used at Sandy Hook Elementary School in Newtown, Conn. The pension fund also owns shares of Sturm, Ruger & Co. and Smith & Wesson Holding Corp., two publicly traded gun-makers.