BASF is selling its 42% interest in an ethylene cracker in Geismar, La., to Williams Olefins, one of its partners in the plant. BASF will sell its stake in pipeline and storage facilities associated with the plant to PetroLogistics. Williams' stake in the complex will double with the purchase. GE Petrochemicals owns the balance. BASF says the 2001 start-up of its joint-venture cracker in Port Arthur, Texas, made the Geismar unit redundant.