* At 9:37 a.m. ET (1437 GMT), the Toronto Stock Exchange's S&P/TSX composite index was down 204.03 points, or 1.15%, at 17,575.38.

* The materials sector, which includes precious and base metals miners and fertilizer companies, lost 2.2% as bullion prices fell on the back of a strong dollar. [GOL/]

* The heavyweight energy sector dropped 0.7%, as U.S. crude prices were down 0.3% a barrel, while Brent crude lost 0.3%. [O/R]

* Celestica Inc fell 8%, the most on the TSX, after the electronics company posted fourth-quarter revenue below analysts' expectations. The second-biggest decliner was fuel-cell products developer Ballard Power Systems Inc, down 8.7%.

* The financials sector slipped 0.8%, while the industrials sector fell 1.8%.

* On the TSX, 15 issues were higher, while 203 issues declined for a 13.53-to-1 ratio to the downside, with 18.50 million shares traded.

* The largest percentage gainers on the TSX were security software maker BlackBerry Limited, which jumped 18.8% and extended a nine-day rally, while apparel maker Canada Goose Holdings Inc added 2.6%.

* The most heavily traded shares by volume were Blackberry, Bombardier Inc , and Supreme Cannabis Company Inc.

* The TSX posted one new 52-week highs and no new lows.

* Across all Canadian issues there were 11 new 52-week highs and 10 new lows, with a total volume of 45.51 million shares.

(Reporting by Amal S in Bengaluru; Editing by Ramakrishnan M.)