Bayer MaterialScience, a world leader in the isocyanate, polyol, elastomeric coatings, adhesives and sealants markets, has decided to go in for downstream expansion, in a bid to strengthen its global strategy to extend products into new markets to meet growing customer requirements. Bayer MaterialScience is to acquire Polythane Systems, Inc. (PSI), a leading supplier of spray polyurethane foam roofing systems in the United States, for an undisclosed amount, by August 31. Bayer's vast resources will combine with PSI's technology and reputation for production and marketing know-how in creating value for customers. Bayer will operate PSI through its wholly owned subsidiary BaySystems North America LLC, and will retain the PSI trade names.