CIBA-GEIGY, PHILLIPS PETROLEUM IN JOINT VENTURE Ciba-Geigy AG <CIGZ.Z> said it would establish a joint venture with Phillips Petroleum Co. In Europe to manufacture a high performance engineering thermoplastic. Initially, the Swiss chemicals firm will manufacture polyphenylene sulfide compounds using resins from Phillips. The two firms will later set up a joint venture to produce the polyphenylene resins and compounds, which will be marketed independently under their respective trademarks. A Ciba-Geigy spokesman declined to say how much the venture would cost. Polyphenylene sulfide is widely used in the electronic, automotive, and petroleum fields.