A government survey showed that growth in China's services sector dropped to a four-month low in December as business expectations fell, adding to figures released earlier this week indicating weakness in the country's manufacturing industry.
After recording a 9.6 percent gain in 2013, the Toronto market declined for a second straight session.
"It's a little bit of a reality check. It probably reflects some position shifting as we begin the new year," said Elvis Picardo, strategist and vice president of research at Global Securities in Vancouver.
"Despite the weak start to the year, I don't think anything fundamental has changed in the outlook for equities."
Investors also paid attention to the U.S. Federal Reserve, whose monetary stimulus helped fuel global equity markets last year.
Ben Bernanke, in what could be his last speech as Fed chairman, said the U.S. central bank is no less committed to highly accommodative policy now that it has trimmed its bond-buying stimulus.
"The markets don't want to see aggressive Fed action," Picardo said. "A lot depends on what the pace of the scaling down is going to be going forward."
The Toronto Stock Exchange's S&P/TSX composite index <.GSPTSE> closed down 45.34 points, or 0.33 percent, at 13,548.85, after slipping to 13,521.75, its lowest since December 27.
Investors realize the need to rethink their expectations at the start of the year after the TSX's robust performance in 2013, its best since 2010.
"It's a good reminder that investors should put things in perspective, make sure that their expectations are appropriately set," said Craig Fehr, Canadian market strategist at Edward Jones in St. Louis, Missouri.
"A year like 2013 skews what investors should be expecting from not only equities, but from a balanced portfolio," he added. "2014 is about readjusting expectations."
Six of the 10 main sectors on the index were in the red in the session.
Energy shares were pulled lower by a drop in the price of U.S. crude oil.
Canadian Natural Resources Ltd (>> Canadian Natural Resources Limited) lost 0.9 percent to C$35.03, having the biggest negative influence on the market. Suncor Energy Inc (>> Suncor Energy Inc.) declined 0.6 percent to C$36.58.
Financials, the index's most heavily weighted sector, were down 0.2 percent. Royal Bank of Canada (>> Royal Bank of Canada), the country's biggest lender, gave back 0.3 percent to C$71.39.
The materials group also stumbled, weighed by a 1.7 percent drop in Goldcorp Inc (>> Goldcorp Inc.).
In corporate news, Canadian Pacific Railway Ltd (>> Canadian Pacific Railway Limited) said late on Thursday it would sell the western part of its Dakota, Minnesota & Eastern Railroad to U.S.-based Genesee & Wyoming Inc (>> Genesee & Wyoming Inc) in a deal worth about $210 million. CP shares edged up to C$159.45.
(Editing by Chris Reese and Chizu Nomiyama)
By John Tilak