Chinese state companies this month began supplying petrol to Iran and now provide up to one third of its imports in a development that threatens to undermine US-led efforts to shut off the supply of fuel on which its economy depends.
The sales come in spite of moves over the past year by international companies, including BP and Reliance of India, to stop selling petrol to Iran, and highlight the difficulties of implementing sanctions aimed at curbing Iran's nuclear ambitions.
Traders and bankers familiar with Iran's purchasing said the gap left by the withdrawal of such long-standing suppliers had been filled by Chinese petrol this month.