In a move that may portend an eventual replacement for CEO Andrew N. Liveris, Dow Chemical has given three members of its executive committee new responsibilities. Howard I. Ungerleider, head of Dow Advanced Materials, will take over as chief financial officer from William H. Weideman, who is retiring. James R. Fitterling, currently head of feedstock, performance plastics, and supply chain, will become vice chairman of business operations. In that role, he will run Dow’s petrochemical and polymer businesses and oversee the divestment of its chlorine and epoxy units. Joe E. Harlan, now head of chemicals, energy, and performance materials, will become vice chairman of market business for Dow. His responsibilities will include Dow AgroSciences, Dow Automotive, electronic materials, and other market-facing businesses.