PETROCHINA Co agreed to its first purchase of crude from Ecuador's state oil company, joining two other international companies that contracted for Ecuadorian oil. PetroChina, China's largest oil company, agreed to buy 720,000 barrels of oil, PetroEcuador said in an e-mailed statement yesterday. Madrid-based Repsol YPF SA contracted for 2.16 million barrels, and Geneva-based Taurus Petroleum Ltd bought 720,000 barrels, the company said. The oil will be shipped in July and August.