Doosan Heavy Industries & Construction Co Ltd, a South Korean power generation facilities builder, said it signed an $80m deal on Tuesday to build a seawater desalination plant in Saudi Arabia.Under the contract with Marafiq, a state-run Saudi company, Doosan will complete the multi-effect distillation (MED)-type plant, to be built in Yanbu, some 350 kilometres (220 miles) northwest of Saudi Arabia\'s second-largest city of Jeddah, in March 2014. The plant will be able to produce 54,000 tonnes of fresh water a day, Doosan said in a statement.The contract came after Doosan in February obtained another order from Saudi Arabia to construct a similar MED-type desalination plant capable of producing 68,000 tonnes of fresh water per day in Yanbu, the company added.