French utilities giant Veolia said on Tuesday it had won a 10-year contract to produce 47 million gallons of desalinated water a day for a petrochemical plant in Saudi Arabia.

The contract is worth 300 million euros ($392 million) and covers the construction and operation of a desalination plant serving a vast petrochemical facility in Saudi Arabia.

The group said its Veolia Water subsidiary had won the contract from Saudi power and water utility company Marafiq for the plant at the Sadara petrochemical facility.

The petrochemical installation is jointly operated by Dow Chemical of the United States and Saudi Arabian oil giant Aramco.

The plant, to go online in 2015, will produce 178 million litres (47 million US gallons) of water per day for use in the plant's cooling towers and boilers.

Veolia is a world leader in water services and a global player in waste management and public transportation.