* May Iran crude imports at 541,510 T vs 284,327 T yr ago
* Jan-May imports from Iran drop 2 pct y/y
* Imports 136,775 T from Mexico, 133,203 T from U.S.
* Total May crude imports at 12.9 mln T, up 32 pct y/y
By Meeyoung Cho
SEOUL, June 15 (Reuters) - South Korean imports of Iranian crude nearly doubled in May from a year ago, but its shipments from the OPEC country in the first five months of 2015 fell 2 percent year-on-year, meeting international sanction requirements.
South Korea and other Asian buyers can import crude from Tehran at sanctions-reduced rates reached in 2013. The United States and five other world powers face a June 30 deadline for a final deal with Iran on curbing its nuclear programme.
Seoul imported 541,510 tonnes of crude from Iran last month, or 128,041 barrels per day (bpd), compared with 284,327 tonnes, or 67,230 bpd, a year ago, preliminary customs data from the world's fifth-largest crude importer showed on Monday.
Of South Korea's four refiners, only SK Energy Co Ltd and Hyundai Oilbank Co Ltd import Iranian oil, and their imports fluctuate each month.
Asia's No.4 economy brought in 2.46 million tonnes, or 119,395 bpd, of crude from the Middle Eastern country between January and May this year, below 2.51 million tonnes, or 121,868 bpd, in the same period last year.
South Korean crude shipments from the Islamic country in 2014 were 6.2 million tonnes, or 124,497 bpd, down 7.1 percent from the 2013 average of 134,000 bpd.
South Korea imported 136,775 tonnes from Mexico in May, paying $56 per barrel on average, according to Reuters calculations based on the customs data.
The data showed South Korea's Mexican crude shipments stood at 688,817 tonnes, or 5 million bpd, in January-May this year, the volume Mexican state oil company Pemex has said it exported to two South Korean refiners, Hyundai Oilbank and GS Caltex Corp.
Pemex in May said it had signed another contract to export an additional 5 million barrels to Hyundai Oilbank in the second half of this year. Separately a spokeswoman at SK Innovation , owner of SK Energy, said last month that one cargo of Mexican crude was on the way to SK Energy.
From the United States, South Korea imported 133,203 tonnes of condensate last month at $59.2 per barrel on average, Reuters calculations based on the customs data showed. That marked the first shipment from the United States since Seoul brought in a combined 215,994 tonnes in September-November 2014. ID:nL3N0YJ1QT]
Overall, South Korea imported 12.9 million tonnes of crude last month, or 3.06 million bpd. That was 32.4-percent higher than the 9.76 million tonnes imported in May 2014, the customs data showed.
Final data for last month's imports, which will include greater detail, will be available from state-run Korea National Oil Corp later this month. (Reporting by Meeyoung Cho; Editing by Joseph Radford)