March 19 (Reuters) - Canada's main stock index fell on Monday, led by the materials and energy sectors as oil prices slipped, and investors were cautious ahead of a near-certain U.S. interest rate hike this week.
* At 9:48 a.m. ET (1348 GMT), the Toronto Stock Exchange's S&P/TSX Composite Index .GSPTSE fell 57.83 points, or 0.37 percent, to 15,653.5.
** Oil prices eased on Monday after rallying at the end of last week, but tensions between Saudi Arabia and Iran helped limit losses. O/R
* The TSX posted no new 52-week highs and one new low. Across all Canadian issues there were 6 new 52-week highs and 8 new lows.
* The largest percentage gainer on the TSX was Canopy Growth Co WEED.TO , which rose 3.4 percent, while the largest decliner was First Quantum Min FM.TO , down 3.3 percent.
* Among the most active Canadian stocks by volume were Neovasc Inc NVCN.TO , up 2.9 percent at $0.18; Klondex Mines KDX.TO , up 66.7 percent at $11.07.
** Gold miner Klondex was up after U.S. miner Hecla Mining Co HL.N said it would buy the company in a $462 mln cash-and-stock deal.
* Volume on the TSX index was 17.83 million shares, while total volume on Monday was 33.64 million shares.