* June crude imports from Iran at 531,200 bpd, up 38 pct y/y
* June crude imports lowest since Feb, down 30 pct m/m
* Jan-June imports from Iran at 627,742 bpd, up 48 pct y/y
* State refiner Sinopec may have cut imports in June -source (Adds comment and recasts)
BEIJING, July 21 (Reuters) - China's crude imports from Iran in the first half of the year were up nearly 50 percent, although shipments in June dropped nearly a third from May to the lowest level in four months.
China, Tehran's largest oil client, began stepping up purchases from the OPEC member after a preliminary nuclear deal in November of last year eased some sanctions on Iran. China has been making up the main portion of Asia's higher Iranian oil imports since then.
Iran and six world powers have failed to negotiate a final resolution to a decade-old standoff over Tehran's atomic activities, but talks have been extended for another four months past the July 20 deadline.
Mostly owing to China's increases since the interim deal was agreed, Asian buyers are expected to import about 1.25 million to 1.3 million barrels per day (bpd) of Iranian oil in the first half of the year, industry and government sources have said.
China's June imports from Iran came in at 2.18 million tonnes, or 531,200 bpd, up 38 percent from a year ago and down 30 percent from May, customs data showed on Monday.
Imports from Iran for the first half of the year were 627,742 bpd, up 48 percent from 424,183 bpd over the same six months of last year, the data showed.
June's level eased back to a normal contract rate versus record and near-record shipments seen in April and May, as top state refiner Sinopec Corp may have slowed down loading from Iran, according to a source.
Sinopec had been planning to cut back its June shipments from Iran because of the high volumes of the previous two months, the trading source familiar with loading plans had earlier told Reuters.
China's imports from Iran spiked to a record in April and remained high in May. June's figures were at the lowest since February, on par with December-March daily imports and near pre-2012 levels, before tough Western sanctions were imposed.
Sinopec has been lifting more Iranian crude since last year partly because it is cheaper versus similar grades from Saudi Arabia, industry officials have told Reuters.
Sinopec's increased shipments helped lift overall imports from Iran and were a result of both the easing of sanctions and a push to cut purchase costs, the officials said.
Higher imports of condensate, a light crude oil from Iran's South Pars gas project, have also contributed to strong intake figures. China counts condensate as crude oil.
Despite the slow progress on a long-term deal to end the decade-old nuclear standoff, Iran has moved to eliminate its most sensitive stockpile of enriched uranium gas, in keeping with the interim agreement, according to an update by the U.N. nuclear watchdog obtained by Reuters.
Iran's overall crude oil exports dropped in June after a spike in May, yet sales were still above the 1 million bpd allowed by the November deal aimed at curbing Tehran's nuclear programme, according to sources who track tanker movements.
Iran ranks No.3 among China's top suppliers, according to customs, with growth in the January-June period the fastest among China's top suppliers, outpacing that of Iraq, Oman, Angola, Russia and Saudi Arabia. (Reporting By Beijing Newsroom; Editing by Tom Hogue)