By Chibuike Oguh and Amanda Cooper

NEW YORK/LONDON, Feb 19 (Reuters) - An index of global shares was lower on Wednesday, pressured by a retreat in Wall Street and European stocks, as U.S. President Donald Trump's latest tariff threats on auto, semiconductor and pharmaceutical imports injected a sense of caution into the markets.

Since his inauguration four weeks ago, Trump has imposed a 10% tariff on all imports from China, on top of existing levies. He has also announced, and delayed for a month, 25% tariffs on goods from Mexico and non-energy imports from Canada.

Trump told reporters on Tuesday that sector-wide tariffs on pharmaceuticals and semiconductor chips would start at "25% or higher", rising substantially over the course of a year. He intends to impose similar tariffs on autos as soon as April 2.

The Dow Jones Industrial Average .DJI fell 0.33% to 44,405.85, the S&P 500 .SPX fell 0.25% to 6,114.14 and the Nasdaq Composite .IXIC fell 0.45% to 19,950.91.

Stocks in Europe extended losses as a rally in drugmakers and miners faded, adding to pressure from a broad-based decline in UK equities after data showed a pickup in British inflation. The STOXX 600 .STOXX was last down 0.9%. Both the S&P 500 and STOXX 600 indexes had finished at record highs on Tuesday.

MSCI's gauge of stocks across the globe .MIWD00000PUS fell 0.41% to 884.10.

"In general the bias for markets remains upwards but if you look shorter term over the last few days, it's more mixed because the market tends to trade around the latest indications of the Trump administration," said Julian McManus, portfolio manager at Janus Henderson Investors.

"That tends to be unsettling and markets tend to trade off whenever they hear the word tariff because they think it means either risk for a particular country or they think inflation."

(Reporting by Chibuike Oguh in New York; Additional reporting by Ankur Banerjee in Singapore; Editing by Tomasz Janowski, Helen Popper and Angus MacSwan)

((amanda.cooper@thomsonreuters.com; +442031978531; Bluesky: @acoops.bsky.social;))