Losses intensified on the Toronto stock market near midday as worries grew over whether Greece could be headed for a debt default.
The S&P/TSX composite index fell 254.17 points to 14,553.92, near its lows of the session.
Read: Greek pensioners swarm banks
Greek Prime Minister Alexis Tsipras made a surprise call for a referendum next Sunday focused on reform proposals the country’s creditors demand should be taken to get access to blocked bailout funds.
In the meantime, strict controls have been placed on capital, with Tsipras closing banks and the country’s stock market for the week.
Some of the biggest decliners on the TSX were financial stocks after bank stocks in Europe took a hit earlier in the day.
Read: Greece, creditors deadlocked
On Wall Street, traders reacted to the growing uncertainty and its impact across the globe.
The Dow Jones industrial average was down 191.68 points at 17,755.34, the Nasdaq index fell 59.01 points to 5,021.49, and the S&P 500 slid 21.12 points to 2,080.37.
In commodities, the crude contract dropped $1.16 at US$58.47 a barrel and the August gold contract rose $4.60 to US$1,177.80 an ounce.
Read: ECB increases amount of emergency loan to Greece
The Canadian dollar was down 0.39 of a U.S. cent to 80.81 cents.
Greek uncertainty weighed heavy across the globe, with Asian and European markets also lower.