WorleyParsons Limited (WOR) has estimated the contract revenue from its Ma’aden Phosphate Project in Saudi Arabian has increased from US$67 million to US$117 million. The mining services company said it receives half of the total contract revenue through its 50 per cent stake in WorleyParsons Arabia. The company said the change orders had arisen due to construction of the phosphate mine, chemicals complex and mine site extending for a longer period than originally estimated. WorleyParsons Arabia said it will provide additional services to the site team up until 31 December 2009 and also provide project management services for related infrastructure as part of its contract.