Chemical maker Saudi Basic Industries (Sabic), the world’s biggest chemical maker by market value, announced plans for a US$1.7 billion joint venture with China Petroleum & Chemical Corp, also know as Sinopec, Bloomberg reported. The joint venture will build an ethylene derivatives plant in the northern Chinese city of Tianjin by the end of the year. According to an intial agreement signed in January, Riyadh-based Sabic will have a 50% stake in the plant. Ethylene and polyethylene are used to make products like auto parts, packing and plastics. Oil giant Exxon Mobil predicts China will account for 25% of the world’s global chemical demand by 2015.