The S&P/TSX Composite index was down nearly 80 points in choppy trade at midday, with the mining sector the worst performer.
The mining sector is down 3.5%, as precious metals prices also trade lower.
The best performers are industrials (+2%) and telecoms (+1.8%).
In economic news, Canadian housing starts this year are expected to fall below last year's levels, as elevated uncertainty, higher development costs, weaker demand and rising unsold inventories continue to weigh on new construction activity, Canada Mortgage and Housing Corporation (CMHC) said Thursday.