The Toronto Stock Exchange's S&P/TSX composite index closed down 23.26 points, or 0.14 percent, at 16,082.09, adding to modest losses since posting a record high close on Tuesday at 16,131.79.
The index has rallied 7.5 percent since September, buoyed by a rally in crude oil prices, while investors have worried less that a slowdown in the housing market will weigh on the outlook for bank shares.
"It's had a very nice run here. I think (the rally) may have gotten tired," said John Kinsey, portfolio manager at Caldwell Securities. "The U.S. didn't help out."
Wall Street ended lower as investors turned their attention to a U.S. Senate Republican plan that would delay corporate tax cuts that investors want very much.
The materials group, which includes precious and base metals miners and fertilizer companies, lost 0.8 percent, with Pan Am Silver shedding 6.2 percent to C$19.07 after reporting weaker-than-forecast quarterly results.
Six of the index's 10 main groups ended lower.
The heavyweight financial services sector dipped 0.1 percent despite a 4.1 percent gain for the shares of Manulife Financial Corp's to C$27.47 after the company late on Wednesday reported quarterly results that beat estimates.
The energy group edged up 0.1 percent as U.S. crude prices settled 0.6 percent higher at $57.17 a barrel.
Tourmaline Oil Corp jumped 7.8 percent to C$26.83 after reporting third-quarter results.
Magna International fell 1.2 percent to C$67.05 after warning that part of its transmission business could soften over the next couple of years.
Luxury apparel maker Canada Goose Holdings Inc surged 13.6 percent to C$31.41 after reporting quarterly earnings that exceeded analysts' forecasts.
Canadian Tire Corp Ltd also gained, rising 3.1 percent to C$162.42 after reporting a rise in quarterly retail sales.
(Additional reporting by Solarina Ho; Editing by Lisa Von Ahn and James Dalgleish)
By Fergal Smith