CP Rail climbed 2.3 percent to a record high after reporting an increase in second-quarter earnings as it worked to recover from backlogs and a harsh winter. The shares closed at C$202.33.

The market eased from an all-time high it hit earlier in the session after concerns grew about the implications of a wave of sanctions that Western powers imposed on Russia.

Further, a Malaysian airliner was brought down over eastern Ukraine, killing all 295 people aboard.

Also working into the mix were figures that showed the number of Americans filing new claims for unemployment benefits fell unexpectedly last week. But U.S. data also showed a drop in housing starts and building permits last month.

“The Ukraine/Russia situation has once again come to the forefront. We've seen a bit of a flight to safety," said Elvis Picardo, strategist and vice president of research at Global Securities in Vancouver.

The Canadian benchmark index has gained about 12 percent this year, driven by a rally in shares of oil and gas companies and gold miners.

“There has been a sea change in the sentiment for the TSX, and it could continue to benefit from its leverage to global growth,” Picardo said.

The Toronto Stock Exchange's S&P/TSX composite index closed down 21.86 points, or 0.14 percent, at 15,204.48, after touching a record high of 15,269.39 earlier in the session.

Eight of the 10 main sectors on the index were in the red on Thursday.

Shares of energy producers gave back 1.2 percent, shrugging off a higher U.S. crude oil price. Canadian Natural Resources Ltd dropped 1.4 percent at C$47.45.

Financials, the index's most heavily weighted sector, slipped 0.2 percent, with Bank of Nova Scotia losing 0.5 percent to C$72.89.

The gold-mining sector soared with the bullion price. Goldcorp Inc rose 2.8 percent to C$30.26, and Barrick Gold Corp added 1.7 percent to C$20.63.

Loblaw Cos Ltd named Executive Chairman Galen Weston president of the grocery chain, replacing Vicente Trius. The stock fell 0.7 percent to C$48.96.

Shares of West Fraser Timber Co Ltd declined 3 percent to C$49.75, a day after the company reported quarterly results.

($1=$1.07 Canadian)

(Editing by Peter Galloway and James Dalgleish)

By John Tilak