The S&P/TSX composite index dropped 60.53 points to 15,509.39.
The Canadian dollar tumbled 0.77 of a cent to 91.13 cents US as the American currency strengthened across the board in the wake of tepid job creation data Friday and worries about the future of the United Kingdom.
New York markets were largely lacklustre with the Dow Jones industrials down 25.94 points at 17,111.42. The Nasdaq was up 9.39 points at 4,592.29, while the S&P 500 index fell 6.17 points to 2,001.54.
Traders sharpened their focus on the U.K. after a YouGov poll showed rising support for Scottish independence. The British pound dropped to a 10-month low against the greenback (US$1.6103), with markets getting increasingly concerned that the gap between the Yes and No sides has narrowed considerably just days before the Sept. 18 referendum.
"It’s hard to say how this will play itself out, but the market is taking notice of the fact particularly since we have seen the U.K. economy really rebound," said Craig Fehr, Canadian markets specialist at Edward Jones in St. Louis.
"So to see a disruption come out of a pocket of strength for the global economy would be a little disheartening for the market."
A Yes vote in the referendum would end Scotland’s 307-year-old union with England and plunge Britain into uncharted constitutional and economic waters.
There were concerns about domestic demand in the wake of the latest trade data from the world’s second-biggest economy. Chinese exports rose 9.4 per cent in August from a year earlier, but imports dropped 2.4 per cent.
Some economists say additional stimulus is needed to prevent China’s growth rate from waning after mini-stimulus measures helped it tick up to 7.5 per cent in the second quarter.
"We would like to see a bit more robust demand and I think, ultimately, there are going to be a lot of policy efforts aimed at doing that," added Fehr.
"But they’re playing a balanced game of trying to let some air out of the property bubble while still stimulating domestic demand. It’s a tricky dance to execute."
The energy sector led TSX decliners, down 1.5 per cent as the stronger American currency and weak Chinese trade data helped push October crude on the New York Mercantile Exchange down 63 cents to US$92.66 a barrel.
The gold sector faded about 2.25 per cent, adding to last week's tumble of almost seven per cent as bullion prices continue to slide amid an environment of low inflation and more willingness to take on risk. December bullion moved $13 lower to US$1,254.30 an ounce. Centerra Gold (TSX:CG) dropped 39 cents to C$6.16.
The metals and mining sector moved down 0.5 per cent as December copper closed unchanged at US$3.17 a pound.
The TSX found limited support from the industrials sector with Bombardier (TSX:BBD.B) up two cents to $3.65 after the transportation company said that test flights had resumed for its CSeries aircraft on Sunday. The aircraft was grounded for more than three months due to an engine failure related to a problem with oil lubrication. Bombardier says the CSeries entry into service is still on track for the second half of 2015.