(Updates to market open prices)

By Ragini Mathur

Dec 17 (Reuters) - Canada's main stock index fell on

Tuesday, weighed down by energy and materials stocks, as the

country's political turmoil turned investors risk averse.

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

fell 0.3% to 25,069.93 points - a near four-week low.

Political worries in Canada escalated following the minority

Liberal government's loss in a British Columbia special

election, further complicating the situation for Prime Minister

Justin Trudeau.

This comes in the wake of the unforeseen resignation of

Finance Minister Chrystia Freeland on Monday.

"There's a lot of turmoil in Canada right now," said Shiraz

Ahmed, senior portfolio manager and founder of Sartorial Wealth

at Raymond James.

"On top of that, the Bank of Canada's super-sized rate

cut is not showing very positive signs for the economy as a

whole. Overall, there seems to be a bit of unrest in the

market."

Canada's annual inflation rate unexpectedly slowed by a

tick to 1.9% in November, due to a general slowdown in prices,

with the consumer price index remaining steady on a monthly

basis.

The data was the first of two inflation reports that the

Bank of Canada will get to assess before its next rate decision

on Jan. 29. The central bank has cut interest rates by 50 basis

points at each of its last two policy announcements.

Heavyweight energy stocks fell the most, down

3.3%, after oil prices dipped as Chinese economic data renewed

demand concerns.

Materials stocks were also down as gold slipped

under pressure from a strengthening U.S. dollar and climbing

Treasury yields.

South of the border, U.S. retail sales increased more than

expected in November amid an acceleration in motor vehicle

purchases.

All eyes will be on the Fed's policy decision on Wednesday,

when policymakers are expected to cut rates by 25 basis points,

a third reduction in borrowing costs since the U.S. central bank

embarked on its easing cycle in September.