Shares of automakers fell Wednesday after BMW warned of lower profits, citing international trade tension and the potential impact of Brexit as possible drags on global economic growth.

BMW executives said the industry faces a fiercely competitive environment, dogged by questions about how tariffs and trade tension between the U.S., China and Europe could affect supply chains, manufacturing and sales.

The news comes one day after FedEx executives expressed worries over a slowing global economy.

All three Detroit automakers declined in morning trading Wednesday. Shares of Ford fell 2.3 percent, Fiat Chrysler fell 2 percent and General Motors dipped 2.6 percent.

"Political and economic developments in Europe remain increasingly uncertain," BMW said in its annual report Wednesday. It specifically cited the "unforeseeable impact of Brexit" and U.S. trade tensions with the European Union and China.

Politico also reported Wednesday that President Trump has the legal grounds impose tariffs on cars imported to the United States, further spooking investors.

"A possible introduction of further trade barriers, including anti-dumping customs duties and duties aimed at protecting national security by the U.S. administration, could have a significantly adverse impact on the BMW Group's operations through less favorable conditions for importing vehicles," BMW said. "Moreover, countermeasures by the USA's trading partners could slow down global economic growth and have a greater-than-expected adverse impact on the export of vehicles produced in the USA."

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