Rexam is expanding its plastics packaging business in a tough market & has agreed to purchase a US maker of injection-moulded jars & closures for £83m.The purchase of US-based Delta Plastics is part of Rexam's strategy to achieve further economies of scale by growing its plastic packaging business & broaden the company's current product offering to multinational food processors, Rexam's CE Lars Emilson stated in his announcement of the deal. While prices of certain plastic resins, including polypropylene & polyethylene have declined in recent months, elevated oil & natural gas prices & efforts by petrochemical companies to aggressively implement price increases could lead to further increases in plastic resin prices, according to a report by Standard & Poors. In its quarterly report Rexam said it had successfully passed on the increasing cost of raw materials.