A group of smokestack industry players announced yet another e-marketplace consortium. This time it was the plastics industry. BASF, Bayer, Dow, DuPont and Ticona/Celanese announced Wednesday that they have agreed to form a b-to-b online marketplace to deliver resins and services to plastics injection molders. The worldwide market is estimated at $50 billion. Although the e-marketplace includes some of the biggest players, the thermoplastics industry is so fragmented that this venture accounts for less than 20% of the market, industry observers say. A noticeably absent player is industry leader GE Plastics, which so far has preferred to retain control of its own e-commerce efforts. Tim Stojka, president-CEO of Commerx Inc., which operates the PlasticsNet e-marketplace, said he welcomed the announcement. ``It validates online exchanges,'' he said.