July 28 (Reuters) - Canada's main stock index fell on

Tuesday as a pullback in gold and oil prices weighed on

materials and energy shares, while investors also monitored a

spate of corporate earnings.

The S&P/TSX Composite Index was 0.3% lower at

35,457.33 points by 10:01 a.m. ET.

* The materials group, which includes metal

mining shares, fell 2.8% to hit its lowest in a week, and was

the biggest drag on the benchmark.

* Gold prices dropped 1.2%. Oil prices also fell,

with Brent crude slipping 2.4% to its lowest in more

than a week, dragging energy stocks 0.3% lower.

* Tech stocks rose 2.4% and touched their highest

in more than two weeks, led by a 4.7% gain in Celestica ( CLS )

after the AI infrastructure firm exceeded second-quarter profit

estimates on Monday.

* TFI International ( TFII ) also beat quarterly adjusted

earnings estimates, pushing the logistics provider shares up

5.5% and making it the top gainer among industrial stocks

.

* The focus remains on fresh corporate earnings, with

multiple miners and energy firms, including First Quantum

and Cardinal Energy, set to report quarterly

results after the bell.

* Investors are also weighing the impact of U.S. President

Donald Trump's new tariffs on Canada, unveiled earlier this

month.

* "We don't expect the recently announced U.S. tariffs to

significantly change broader Canadian growth trends if imposed

as threatened," strategists at RBC Economics said, adding they

expect aggregate growth to improve in the second half and the

unemployment rate to trend downward.

* Markets will also tune in to the U.S. Federal Reserve

meeting on Wednesday, where the central bank is expected to keep

interest rates unchanged.