(Updates with morning prices)

By Nikhil Sharma

March 11 (Reuters) - Canada's main stock index fell on

Tuesday, as investors priced in U.S. President Donald Trump's

announcement of additional tariffs on Canadian metals.

The Toronto Stock Exchange's S&P/TSX composite index

was down 0.28% at 24,313.03.

Trump on Tuesday doubled his planned tariff on all steel and

aluminum products coming into the United States from Canada,

bringing the total to 50%, in response to the Ontario province

placing levies on electricity coming into the U.S.

"It's obviously not good. The market is anticipating a

slowdown in future growth and it's trying to price it in," said

Allan Small, senior investment advisor at Allan Small Financial

Group with iA Private Wealth.

"The President is sticking to his guns and doing what he

said he was going to do and (he is) not really, at this point in

time, concerned about the ramifications."

Investors are also looking towards the Bank of Canada's

monetary policy decision on Wednesday, with traders expecting

the central bank to support the economy by cutting interest

rates by 25 basis points.

The benchmark index fell to a four-month low on Monday due

to worries that Trump's tariffs on key trade partners such as

Canada and Mexico have triggered risks of recession for all

three countries.

"There's a very clear risk off mentality at the moment,"

said Josh Sheluk, portfolio manager at Verecan Capital

Management.

The materials index gained 2.5%, largely due to a

1% rise in gold prices. Demand for the safe-haven asset soared

amid concerns that global trade tensions stemming from U.S.

tariffs could hurt economic growth.

Precious metal companies such as New Gold ( NGD ) and Aya

Gold & Silver ( AYASF ) were among the biggest gainers on the

main index, rising 7.2% and 10.3%, respectively.

On the other hand, healthcare and consumer

discretionary led losses, falling 2.3% and 1.7%,

respectively.