(Updates shares, add sector details) Jan 27 (Reuters) - Canada’s main stock index slipped on Wednesday, weighed down by weakness in materials and energy stocks, while investors awaited the U.S. Federal Reserve policy statement for clarity on monetary stimulus. * 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. * The heavyweight energy sector dropped 0.7%, as U.S. crude prices were down 0.3% a barrel, while Brent crude lost 0.3%. * 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.)