Saudi Arabia will start work in August on a Gulf coast industrial zone where it plans to build major aluminum and fertilizer export plants, in what officials call the biggest step yet to diversify the oil-driven economy. The head of the state-owned mining firm Maaden, Abdallah Dabbagh, said the site at Ras Al-Zour will be leveled ahead of construction of the 640,000 tons a year aluminum smelter and 3 million tons a year di-ammonium phosphate plant. "This industrial city, with these two projects, is the largest diversification which has ever happened in Saudi Arabia," Dabbagh told Reuters in an interview yesterday. The site, which will process bauxite and phosphate from mines in northern Saudi Arabia, will be powered by a 1,800 megawatt station. An ammonia plant, alumina refinery and six plants producing sulfuric and phosphoric acid will be built. --MORE 1057 Local Time 0757 GMT