* Industry body gives detail on timing of potential import halt

* Comes as U.S. demands nations stop taking oil cargoes from Iran

* Shippers tell Japan refiners will not carry Iran oil -sources (Adds comment, detail, graphic)

TOKYO, July 19 (Reuters) - Japanese oil refiners will likely stop loading Iranian crude by mid-September with final shipments arriving in the first half of October, the head of the nation’s oil refiners association said on Thursday, as the U.S. pressures countries to halt such imports.

U.S. President Donald Trump’s administration has demanded nations cut all their imports of Iranian oil from November as it reimposes sanctions over Tehran’s nuclear programme.

Although it has said that some allies who are particularly reliant on Iranian supplies may be granted waivers that would give them more time to wind down shipments.

“Japanese oil refiners have been making preparations for lifting plans on the assumption that U.S. sanctions are to be applied,” the president of the Petroleum Association of Japan (PAJ), Takashi Tsukioka, said.

“Considering that payment is to be finished by end of October, it is important that the refiners would finish loading (Iranian oil) before mid-September.”

Tsukioka added that the industry is asking the Japanese government to push to maintain current levels of Iranian imports in talks with the United States. But a Japanese government source, who declined to be identified, said winning a waiver was seen as “difficult”.

PAJ had said last month that Japanese refiners would likely stop importing from Iran, but on Thursday gave more details on potential timings.

Many refiners in Japan, the world’s fourth-biggest oil importer, say they are resigned to completely halting imports from one of their historically important suppliers, unlike during a previous round of sanctions when they substantially reduced imports from the Middle Eastern country.

Three industry sources familiar with the matter said shipping companies had told refiners in Japan that they would stop carrying oil cargoes from Iran. The sources declined to be identified as they were not authorised to speak with media.

That would follow similar announcements by the world’s biggest shipping companies including A.P. Moller-Maersk of Denmark.

Unlike Japan, China and some countries in Europe have significantly raised purchases following the lifting of previous sanctions.

“It would be unreasonable for (Japanese refining) industry to be influenced similarly by such countries,” said Tsukioka, who also serves as chairman of Japan’s second-biggest refiner, Idemitsu Kosan.

Japan’s largest banks had already said they would stop handling all Iran-related transactions to meet the November deadline set by Trump, Reuters reported last week.

Japanese refiners are looking to secure alternative supplies from the Middle East and the U.S. among others, industry sources have said.

Japan last year imported 172,216 barrels per day of Iranian crude, down 24.2 percent from a year earlier, with Iranian oil accounting for 5.3 percent of the nation’s total imports.