NEW YORK, July 3 (Reuters) - Autocatalyst metal platinum tumbled to its lowest level in nearly 10 years on Monday, as the greenback strengthened, an intensifying U.S.-European Union trade spat pressured precious metals, and political risk in Germany weighed. Spot platinum settled at $816 per ounce after earlier dropping more than 5 percent to $804, its lowest level since December 2008. This was the biggest one-day drop since June 2013. Traders said concerns in Germany were a factor. German 10-year bond yields dipped to five-week lows on Monday, pushed down by political uncertainty in Germany, trade war fears and an expectation that the European Central Bank could buy more long-dated bonds from next year to keep euro-zone borrowing costs in check. The pan-European STOXX 600 ended the session down 0.8 percent with losses across the continent and sectors. Germany's trade-sensitive DAX settled down 0.6 percent. A stronger U.S. dollar against a basket of currencies also pressured platinum prices, because it makes greenback-priced precious metals more expensive for holders of other currencies. The dollar received a boost from better-than-expected U.S. manufacturing data earlier on Monday. A deepening auto tariff spat between the United States and the European Union has pressured all precious metals, traders said. The European Union has warned the United States that imposing import tariffs on cars and car parts would harm the U.S. automotive industry and likely lead to counter-measures on $294 billion of U.S. exports. The expectation of higher U.S. interest rates pressured platinum and other precious metals, traders said. Higher rates tend to strengthen the dollar and boost bond yields, reducing the appeal of non-yielding precious metals. The U.S. Federal Reserve is expected to release minutes from its June meeting on Thursday.