(Reuters) -Shares in some of the biggest European carmakers slumped on Monday after U.S. President Donald Trump imposed new tariffs of 25% on goods from Mexico and Canada and 10% on imports from China, raising concern over possible duties on EU imports too.

Volkswagen and Stellantis ( STLA ), which have major operations in Mexico and are particularly vulnerable to tariffs, were both down around 6%, falling the most among peers.

Volvo Cars, Mercedes Benz, BMW, Porsche, were down between around 3.4% and 5.2% at 0843 GMT.

French car parts supplier Valeo slumped 7%.

Europe's automobiles and parts index fell 3.4% to more than two-week lows, leading losses among other sectoral indices on wider Europe's STOXX 600, which slipped 1.3%.

Analysts and experts fear the tariffs on Mexico could be more damaging for European car makers and their suppliers than any direct tariffs on EU goods.

"We believe around 8 billion euros ($8.2 billion) of VW's revenues are impacted by tariffs and around 16 billion euros of Stellantis ( STLA ) revenues," analysts at investment bank Stifel wrote in a note.

They estimated the full impact of tariffs at around 12% of Volkswagen's EBIT in 2025 and 40% of Stellantis' ( STLA ).

Volkswagen said on Sunday it was counting on talks to avoid trade conflict.

JPMorgan analysts said in a note they expected the carmakers to give commitments to the U.S. government on jobs and production of vehicles in the U.S. versus Mexico and Canada this week.

The tariffs are due to take effect 12:01 a.m. ET (0501 GMT) on Tuesday.

($1 = 0.9778 euros)