China Petrochemical Corporation (Sinopec Group) and China National Petroleum Corporation (CNPC) has stopped purchasing Iranian oil in May, according to industry sources, Reuters reported.

The decision of the two corporations comes after the US ended sanction waivers permitted to a number of countries, including China.

“There are no nominations so far…but companies are trying to find some solution, such as offering to top up volumes in later months,” said the source.

China is Iran’s largest oil customer with imports of 475,000 barrels per day (b/d) in Q1 2019, according to Chinese customs data.