The remaining 40 % is done through the purchase of spot contracts. Each month CPC calculates future refining and sales supply and demand, and then, under the competitive tendering process that is required by law, invites bids from the 47 major oil companies and crude oil dealers worldwide that CPC has approved as eligible suppliers.
另有 4 成則是購買現貨，即由中油每月計算未來的煉製、銷售需求量後，依法招標，讓已通過中油審核合格的全球 47 家大型石油公司與原油商來競標。