Singapore, July 10 (SANA) QatarEnergy has cut its official selling prices for August-loading crude cargoes, as increased supplies from the Middle East weigh on oil markets. According to an official pricing document cited by Reuters on Friday, QatarEnergy set the official selling price for Qatar Marine crude at a discount of $5 a barrel against the average price of Oman/Dubai crude. The company priced Qatar Land crude at a discount of $4.50 a bar…