Local officials in Chippewa Falls say the decision to close the Pactiv plant will be difficult for the local economy to absorb. Shutting down the plastics manufacturing operation will cost the region 170 jobs. The Illinois company said yesterday it will phase out operations at that plant by January, shifting the production efforts to other locations. Pactiv makes plastic cups and plates, among other products. Chippewa Falls officials say they hope to be able to sell the building to another company.