Momentive Performance Materials Holdings Inc., the parent company of Momentive Performance Materials Inc., and Hexion LLC, the parent company of Hexion Specialty Chemicals, Inc., jointly announced an agreement under which their newly-formed holding companies will merge, creating a global leader in specialty chemicals and materials. The boards of both holding companies have unanimously approved the merger, which is subject to customary conditions. Closing is anticipated to occur Oct. 1. The ne...