Updates with U.S. market activity

By Tom Polansek

CHICAGO, April 3 (Reuters) - Chicago Board of Trade soybean futures slid on Thursday amid concerns that new U.S. tariffs could trigger retaliatory measures against American exports, analysts said.

President Donald Trump on Wednesday announced a 10% baseline tariff on most imports to the U.S., with higher duties on dozens of trading partners including China and the European Union.

The plan sent share and oil prices falling as investors feared a global recession, while grain traders saw scope for disruption to U.S. agricultural exports, particularly soybeans.

Traders were watching to see whether U.S. soybeans would be targeted in turn by China, the world's biggest soybean importer, and the EU.

"It's negative psychologically," said Rich Nelson, chief strategist for brokerage Allendale.

The most-active soybean contract Sv1 was down 18-1/2 cents at $10.11 a bushel by 12:35 p.m. CDT (1735 GMT). CBOT wheat Wv1 dropped 1-1/4 cents to $5.38 a bushel, while corn Cv1 rose 1/2 cent to $4.58-1/4 a bushel.

Some traders were relieved that Mexico was excluded from Trump's sweeping new tariffs, as it is the biggest export market for U.S. corn. This helped to underpin corn futures, Nelson said.

They also took comfort that Trump did not set a higher baseline tariff level.

"Most of the tariffs have turned out to be more of a fizzle than a bang," said Ole Houe of IKON Commodities in Sydney. "What was initially proposed as a blanket 20% tariff has been reduced to just 10%, which is manageable for most nations."

Still, economists said Trump's tariffs could prove relatively advantageous for Brazil, which is the world's biggest soybean exporter and competes with the U.S. for soy sales to China.

Brazil said it is close to reaching an agreement with Chinese authorities enabling the sale of Brazilian corn-based distiller's dried grains $(DDG)$, which is used as animal feed.

(Reporting by Tom Polansek in Chicago, Gus Trompiz in Paris and Ella Cao and Lewis Jackson; Editing by Sumana Nandy, Janane Venkatraman and Elaine Hardcastle)

((Thomas.Polansek@thomsonreuters.com))