* Imports 420,402 T or 99,405 bpd Iran crude in Oct - customs
* June-Oct imports of Iran crude at 125,167 bpd
* Met daily import target of 125,814 bpd
* Total Oct crude imports at 10.7 mln T, down 4 pct y/y
By Meeyoung Cho
SEOUL, Nov 15 South Korea's Iranian crude imports fell in October from September, meeting a targetted 15 percent cut in its shipments from the OPEC member for the June-November period to secure an extension of its six-month U.S. sanctions waiver.
South Korea, along with other top buyers China and India, is up for renewal of its exemption in December. China, though, has to make sharp cuts in Iran oil imports for the rest of this year as its purchases are up 1.4 percent for the first nine months.
To win waivers on the U.S. sanctions that have helped to halve Tehran's oil exports from pre-2012 levels, Iran's buyers must continually cut their imports despite the Middle Eastern nation's new conciliatory tone on its nuclear programme.
Negotiators from world powers will resume talks with Iran on Nov. 20 after failing this past weekend to agree on an initial proposal to ease international sanctions against Tehran in return for some restraints on its nuclear programme.
South Korea imported 420,402 tonnes of Iranian crude last month, or 99,405 barrels per day (bpd), down more than a quarter compared with September and down nearly a half from a year earlier, preliminary customs data showed on Friday.
That puts the Asian country's imports from Iran for June-October at 125,167 bpd, according to Reuters calculations.
The total means South Korea met the 125,814 bpd it aims to achieve in its imports from Iran in the six months through November.
South Korea and India - which has cut its imports for January-September by 40 percent - look best placed heading into the review period on the waivers next month.
Japan won its fourth six-month waiver in September, although its imports are now up 2 percent on the year over the January-September months.
Analysts say Iranian oil exports are likely to remain under pressure, and some U.S. lawmakers have said they want to tighten sanctions on Iran to prevent Washington giving away too much in any deal on Tehran's nuclear programme.
But U.S. President Barack Obama's administration has been calling for a "temporary pause" on any new sanctions to avoid jeopardising the talks to end the decade-long standoff over Iran's nuclear programme.
The European Union and the United States believe Iran is developing nuclear weapons, while Tehran says its programme is for power generation.
Seoul has vowed to slash Iranian oil imports by 15 percent from the 148,016 bpd imported in December 2012 to May 2013, two sources told Reuters in June.
South Korea's Iranian crude imports vary from month to month as one of the two Korean refiners that buys from Iran receives oil only every other month, according to industry sources. The imports unexpectedly jumped in July from the year-earlier period before dropping off again in August.
SK Energy and Hyundai Oilbank are the only South Korean refiners that take Iranian oil on a regular basis.
South Korea, the world's fifth-largest crude buyer, imported a total of 10.7 million tonnes of crude last month against 11.1 million tonnes in October 2012, data from the Korea Customs Service also showed on Friday.
Final data for South Korea's crude oil imports last month will be published by state-run Korea National Oil Corp later this month. (Reporting by Meeyoung Cho; Editing by Tom Hogue and Richard Pullin)