Iran ranked as South Korea's second-biggest oil exporter over the first three months of 2017 as it ramped up output to regain market share after sanctions were lifted last year, the first time ever it has claimed the No.2 spot for a quarter.

South Korea's March imports from Iran more than doubled from a year ago to a record of 18.54 million barrels, or 597,935 barrels per day (bpd), data from state-run Korea National Oil Corp (KNOC) showed on Monday.

For the January-March period of 2017, Iran seized the No.2 spot with shipments of 46.73 million barrels, also more than double from the same period last year and the highest on record for a quarter.

In the first quarter of 2016, Iran was South Korea's fifth-biggest oil supplier behind Saudi Arabia, Iraq, Kuwait and Qatar, according to KNOC data.

This year's surge in Iranian crude supply came after Tehran was exempted from production cuts led by the Organization of the Petroleum Exporting Countries (OPEC) to clear a global glut.

Iran's jump to the No.2 spot is also due to solid condensate demand from South Korean refiners such as SK Energy and Hyundai Oilbank.

Saudi Arabia held onto its spot as South Korea's top oil supplier for both March and the full quarter.

Shipments from Saudi Arabia rose 10.8 percent in March from a year ago to nearly 26 million barrels, or 838,387 bpd, from 23.46 million barrels last year.

In the first quarter, the world's top oil exporter shipped 77.12 million barrels of crude to South Korea, up 4.4 percent from about 74 million barrels in the same period of 2016, according to the data.

Overall, South Korea's March imports increased 11.7 percent from a year ago to 95.9 million barrels, or 3.09 million bpd, the data showed.

The world's fifth-largest crude importer brought in 278.18 million barrels of crude in the first three months of 2017, up 4.9 percent from 265.3 million barrels last year.

(Source: Reuters)