BEIJING, Aug 25 (Reuters) - China’s exports of rare earth magnets to the United States rebounded in July from the previous month, customs data showed on Sunday, as concerns linger that Beijing could restrict supply of rare earth products in the Sino-U.S. trade war.Shipments totalled 447 tonnes last month, data from the General Administration of Customs showed. That compared to 414 tonnes in June and 356 tonnes in July 2018.China is the world’s dominant producer of rare earth magnets, which are widely used in medical devices and consumer electronics as well as defence. It has raised the prospect of restricting rare earth supply to the United States, although no formal measures have been announced.In retaliatory tariffs on $75 billion of U.S. goods announced late on Friday, China’s Ministry of Finance slapped a 5% duty on imports of permanent rare earth magnets from the United States from Dec. 15, although such imports were at a negligible 4 tonnes in the first half of 2019, customs data show.Tariffs on imports of 11 other rare earth-related items were also introduced.Another key rare earth product for the United States is lanthanum, which is used in the oil-refining industry. Exports of lanthanum oxide stood at 966 tonnes in July, the customs data showed. That was more than double the 433 tonnes in June and up 119.5% from 440 tonnes in July 2018.Exports of lanthanum carbonate, meanwhile, were at 119 tonnes, just below 120 tonnes in June and down 71.9% year-on-year.China’s overall rare earth exports, which can fluctuate wildly, rose by 32.2% in July from the previous month to their highest level since December, according to data released on Aug. 8. (Reporting by Tom Daly and Muyu Xu; Editing by Stephen Coates)