The Toronto stock market plummeted three per cent or 351.03 points to close at 11,408.32 on Thursday, the biggest one day drop since November.
U.S. stocks posted their worst day in three weeks on Thursday on mounting evidence that slowing manufacturing growth worldwide was poised to hurt profit growth.
Based on the latest available data, the Dow Jones industrial average was down 252.93 points, or 1.97 per cent, at 12,571.46. The Standard & Poor's 500 Index was down 30.35 points, or 2.24 per cent, at 1,325.34. The Nasdaq Composite Index was down 71.36 points, or 2.44 per cent, at 2,859.09.
U.S. Treasuries prices rose on Thursday as data pointed to a slowing U.S. economy, a day after the Federal Reserve said it was ready to do more to help an increasingly fragile recovery.
Data reflected an unexpected contraction in factory activity in the U.S. mid-Atlantic region in June. The Philly Fed index of factory activity tumbled to a 10-month low.
Weak job and housing data from the U.S. and signs that China's manufacturing sector is slowing pushed the greenback higher against most major currencies Thursday.
The euro fell to $1.2558 late Thursday from $1.2672 late Wednesday. The British pound fell to $1.5594 from $1.5702.
Brent crude oil slid nearly 4 per cent in heavy trading on Thursday, dropping below $90 a barrel for the first time in 18 months as weak economic data from China, the United States and Europe pointed to prospects for slower oil demand.
U.S. August crude fell $3.25 to settle at $78.20 a barrel, the lowest front-month settlement for U.S. crude since Oct. 4, 2011.
Meanwhile, Bank of Canada governor Mark Carney warned Thursday Canada's relatively healthy economy has been largely based on borrowed money but the situation cannot go on indefinitely.
The central bank governor's stern words to a business audience in Halifax came just hours after federal Finance Minister Jim Flaherty moved to clamp down on household lending by reducing the amortization period on mortgages to 25 years from 30, and by limiting home equity loans.
In the U.S. a financial regulator has fined Merrill Lynch $2.8-million for overcharging customers with fees and for failing to provide timely trade confirmations.
The Financial Industry Regulatory Authority said Thursday that it fined Merrill Lynch, Pierce, Fenner & Smith after it found the broker overcharged nearly 95,000 customer accounts with fees totaling more than $32-million from April 2003 to December 2011.
Google's shareholders are expected to approve on Thursday the company's plan to issue a new class of stock. Google's co-founders, Larry Page and Sergey Brin, and Executive Chairman Eric Schmidt are pushing for the move to ensure that they maintain long-term control of the company.
The plan is expected to pass because Page, Brin and Schmidt have most of the voting power. The proceedings are on the agenda Thursday at Google's annual shareholders meeting at its headquarters in Mountain View, Calif.
With files from Reuters