end from May@ (Adds detail, background)
* April Iranian crude imports rise by 17% to 1.45 mln T
* Jan-April oil imports from Iran at 3.87 mln T, down 17.4% y/y
* No Iranian oil imports from May as U.S. sanction waivers end
* Total April crude imports up by 10.2% y/y at 12.76 mln T
SEOUL, May 15 (Reuters) - South Korea's Iranian oil imports rose 17% in April from a year earlier, customs data showed on Wednesday, but shipments are set to end from May as waivers on U.S. sanctions on Tehran expired at the start of this month.
South Korea in April imported 1.45 million tonnes of crude oil from Iran, or 353,223 barrels per day (bpd), compared to 1.24 million tonnes a year earlier, according to customs data.
For the January-April period, the country's imports of Iranian crude dropped by 17.4% to 3.87 million tonnes, or 235,533 bpd, versus nearly 4.7 million tonnes in the same period last year, the data showed.
South Korea was granted six-month waivers from the United States in November to buy oil from Iran, mostly condensate, or an ultra-light form of crude oil.
However, Washington said in April that it would not renew any exemptions for sanctions on Iran, stepping up pressure on Tehran.
In the wake of that step, South Korean petrochemical makers are expected to scour the world to replace Iranian condensate.
South Korea's overall April crude oil imports were 12.76 million tonnes, or 3.1 million bpd, up 10.2% from 11.58 million tonnes a year earlier.
Its oil shipments from Saudi Arabia, the country's top crude supplier rose 8.5% year-on-year to 3.59 million tonnes, or 874,401 bpd, the data showed.
In a sign that South Korea has been diversifying its import sources, imports from the United States grew five-fold to 1.45 million tonnes in April, or 353,006 bpd, from 268,511 tonnes a year earlier.
In the first four months of the year, the country's crude oil imports increased by 3.4% to 49.91 million tonnes.
The nation's final crude oil imports data will be released later this month from state-run Korea National Oil Corp (KNOC). (Reporting by Jane Chung; Editing by Joseph Radford)