* Asian imports of Iran oil at 1.56 mln bpd last month * Imports by India top 500,000 bpd, highest in five years * South Korean imports nearly double yr/yr * Iran struggles to find enough ships for oil exports By Osamu Tsukimori TOKYO, April 28 (Reuters) - Asian imports of Iranian oil in March jumped 50 percent from a year earlier as shipments into India and South Korea have climbed since international sanctions were lifted on Iran's disputed nuclear programme. The strong exports point to Iran's success in regaining market share in Asia after the sanctions were eased in January. Before 2012, Iran exported around 2 million bpd, with more than half going to Asia, mainly China, South Korea, India and Japan. Tehran has been banned from selling oil to the United States for decades. Iran's oil flows to Europe have also begun to pick up after a slow start though the country has struggled to increase oil exports because many of its tankers are tied up storing crude, some are not seaworthy, and foreign ship owners remain reluctant to carry its cargoes. Imports by Iran's top four buyers - China, India, Japan and South Korea - came to 1.56 million bpd in March, up 49.9 percent from a year ago, government and tanker-tracking data shows. India's imports last month totalled 506,100 bpd, the highest in five years, the data showed. The nation's imports from Iran are set to surge to a seven-year high during the fiscal year of 2016/17, industry sources said. South Korea's imports in March fell slightly from a two-year high in February to 264,452 bpd but were still 94.5 percent higher than a year ago. Imports by China and Japan fell from a year ago. The following tables show Asia's Iran crude imports in bpd for last month and the year to date. Nation Mar-16 Mar-15 yr/yr pct China 590,830 638,600 India 506,100 - n/a Japan 198,355 266,144 -25.5 Korea 264,452 135,935 Total 1,559,737 1,040,679 49.9 Nation Jan-Mar 2016 Jan-Mar 2015 yr/yr pct China 511,757 547,110 India 299,200 126,000 Japan 209,871 227,990 -7.9 Korea 251,088 113,911 Total 1,271,916 1,015,011 25.3 (Reporting by Osamu Tsukimori; Editing by Christian Schmollinger)