* Asia imports 1.64 mln bpd in Aug, down 10.8 pct yr/yr
* China monthly imports highest since 2006
* India imports hit 18-month low in retaliation to Iran
* Korean imports hit 5-month high
* Japan imports tumble 54.4 pct yr/yr
TOKYO, Sept 29 (Reuters) - Imports of Iranian crude by major buyers in Asia rose for a second month in a row in August to hit their highest level since March, helped by a spike in purchases However, imports by Asia's four main buyers remained below year ago levels for a fourth month in a row, the first time this has happened since Western sanctions against Tehran were lifted in January last year, leading to a surge in shipments. China, India, South Korea and Japan together imported 1.64 million barrels per day (bpd) last month, down 10.8 percent on a year ago, government and ship-tracking data showed. Iran aims to maintain crude oil and condensate exports at around 2.6 million bpd for the rest of 2017 although recent maintenance, depleted oil storage and a growing domestic appetite will limit shipments abroad, a senior official at the national state oil company said on Monday. Chinese imports rose 5.5 percent from a year ago last month to 786,720 bpd, the highest monthly amount since 2006, according to data on Reuters Eikon. South Korea's imports jumped 46.7 percent to a five-month high of 407,323 bpd. India, however, continued to reduce its intake in retaliation at Tehran's decision to award a giant gas field to a Russian company. India imported 335,400 bpd in August, the lowest level since February 2016, and down about 42 percent from a year ago. Japan's Iranian imports fell for a fourth straight month from a year ago to 107,357 bpd, the lowest volumes since April, trade ministry data showed on Friday. Iran has been exempted from an agreement by the Organization of the Petroleum Exporting Countries (OPEC) to reduce output, a victory for Tehran which has argued it needs to regain the market share it lost under Western sanctions over its disputed nuclear programme. Iran is aiming to raise oil output to around 4 million bpd from around 3.8 million bpd in recent months.
The following tables show Asia's Iran crude imports in bpd for last month and the year to date.
Nation Aug-17 Aug-16 yr/yr pct China 786,720 746,029 5.5 India 335,400 575,900 -41.8 Japan 107,357 235,612 -54.4 Korea 407,323 277,613 46.7 Total 1,636,800 1,835,154 -10.8 Nation Jan-Aug 2017 Jan-Aug 2016 yr/yr pct China 609,886 614,703 -0.8 India 497,600 394,700 26.1 Japan 159,196 216,101 -26.3 Korea 413,337 269,803 53.2 Total 1,680,019 1,495,307 12.4
(Reporting by Osamu Tsukimori; Editing by Richard Pullin)