South Korea's imports of Iranian oil fell nearly half in May from the previous month as local refiners moved to switch their suppliers in the face of international sanctions against Tehran, industry data showed Sunday.

South Korea imported 3.96 million barrels of Iranian crude in May, down 47.3 percent from 7.52 million barrels in April, according to the data compiled by the Korea National Oil Corp. (KNOC).

It is the lowest monthly tally since October 2010 when the country bought 3.72 million barrels of oil from Iran.

The KNOC data showed that the average price for a barrel of Iranian crude reached US$116 in the cited month, down 4.92 percent from April.

"As the United States and Europe increased pressure over Iran, local refiners tried to diversify their imports and decreased crude imports from the Middle Eastern country," said an industry source who declined to be identified.

Local refiners instead bought 5.38 million barrels of crude from the United Arab Emirates, up 69.6 percent from the previous month, while oil shipments from Kuwait jumped 37.3 percent on-month to 13.3 million barrels and imports from Saudi Arabia rose 20.2 percent on-month, the data showed.

Late last month, South Korea said it will halt oil imports from Iran from July in line with the European Union's sanctions on insurance for Iranian oil shipments. European firms cover 100 percent of protection and indemnity insurance on all Iranian oil shipments to South Korea.

KNOC said that South Korea imported a total of 389.4 million barrels of crude oil during the January-May period, with the average price reaching $116.89 per barrel. (Yonhap News)